Organic compounds

ABSTRACT

The present invention relates to optionally substituted 3-amino-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6(7H)-ones and their 4-imino or 4-thioxo derivatives, e.g., 3-amino-4-(thioxo or imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, 3-amino-4-(thioxo or imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, 3-amino-4-(thioxo or imino)-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, processes for their production, their use as pharmaceuticals and pharmaceutical compositions comprising them.

This application is a continuation application of U.S. application Ser. No. 13/132,955, filed Jun. 6, 2011 under 35 U.S.C. §371 which claims benefit to PCT Application No PCT/US2009/006444, filed on Dec. 7, 2009, which claims priority from U.S. Provisional Application No. 61/120,438, filed Dec. 6, 2008, the contents of each of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to optionally substituted 3-amino-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6(7H)-ones and their 4-imino or 4-thioxo derivatives, e.g., 3-amino-4-(thioxo or imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, 3-amino-4-(thioxo or imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, 3-amino-4-(thioxo or imino)-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, preferably, a compound of Formula I as described below, processes for their production, their use as pharmaceuticals and pharmaceutical compositions comprising them. Of particular interest are novel compounds useful as inhibitors of phosphodiesterase 1 (PDE1), e.g., in the treatment of diseases involving disorders of the dopamine D1 receptor intracellular pathway, such as Parkinson's disease, depression, narcolepsy, damage to cognitive function, e.g., in schizophrenia, or disorders that may be ameliorated through enhanced progesterone-signaling pathway, e.g., female sexual dysfunction.

BACKGROUND OF THE INVENTION

Eleven families of phosphodiesterases (PDEs) have been identified but only PDEs in Family I, the Ca²⁺-calmodulin-dependent phosphodiesterases (CaM-PDEs), have been shown to mediate both the calcium and cyclic nucleotide (e.g. cAMP and cGMP) signaling pathways. The three known CaM-PDE genes, PDE1A, PDE1B, and PDE1C, are all expressed in central nervous system tissue. PDE1A is expressed throughout the brain with higher levels of expression in the CA1 to CA3 layers of the hippocampus and cerebellum and at a low level in the striatum. PDE1A is also expressed in the lung and heart. PDE1B is predominately expressed in the striatum, dentate gyms, olfactory tract and cerebellum, and its expression correlates with brain regions having high levels of dopaminergic innervation. Although PDE1B is primarily expressed in the central nervous system, it may be detected in the heart. PDE1C is primarily expressed in olfactory epithelium, cerebellar granule cells, and striatum. PDE1C is also expressed in the heart and vascular smooth muscle.

Cyclic nucleotide phosphodiesterases decrease intracellular cAMP and cGMP signaling by hydrolyzing these cyclic nucleotides to their respective inactive 5′-monophosphates (5′AMP and 5′GMP). CaM-PDEs play a critical role in mediating signal transduction in brain cells, particularly within an area of the brain known as the basal ganglia or striatum. For example, NMDA-type glutamate receptor activation and/or dopamine D2 receptor activation result in increased intracellular calcium concentrations, leading to activation of effectors such as calmodulin-dependent kinase II (CaMKII) and calcineurin and to activation of CaM-PDEs, resulting in reduced cAMP and cGMP. Dopamine D1 receptor activation, on the other hand, leads to activation of nucleotide cyclases, resulting in increased cAMP and cGMP. These cyclic nucleotides in turn activate protein kinase A (PKA; cAMP-dependent protein kinase) and/or protein kinase G (PKG; cGMP-dependent protein kinase) that phosphorylate downstream signal transduction pathway elements such as DARPP-32 (dopamine and cAMP-regulated phosphoprotein) and cAMP responsive element binding protein (CREB). Phosphorylated DARPP-32 in turn inhibits the activity of protein phosphates-1 (PP-1), thereby increasing the state of phosphorylation of substrate proteins such as progesterone receptor (PR), leading to induction of physiologic responses. Studies in rodents have suggested that inducing cAMP and cGMP synthesis through activation of dopamine D1 or progesterone receptor enhances progesterone signaling associated with various physiological responses, including the lordosis response associated with receptivity to mating in some rodents. See Mani, et al., Science (2000) 287: 1053, the contents of which are incorporated herein by reference.

CaM-PDEs can therefore affect dopamine-regulated and other intracellular signaling pathways in the basal ganglia (striatum), including but not limited to nitric oxide, noradrenergic, neurotensin, CCK, VIP, serotonin, glutamate (e.g., NMDA receptor, AMPA receptor), GABA, acetylcholine, adenosine (e.g., A2A receptor), cannabinoid receptor, natriuretic peptide (e.g., ANP, BNP, CNP), DARPP-32, and endorphin intracellular signaling pathways.

Phosphodiesterase (PDE) activity, in particular, phosphodiesterase 1 (PDE1) activity, functions in brain tissue as a regulator of locomotor activity and learning and memory. PDE1 is a therapeutic target for regulation of intracellular signaling pathways, preferably in the nervous system, including but not limited to a dopamine D1 receptor, dopamine D2 receptor, nitric oxide, noradrenergic, neurotensin, CCK, VIP, serotonin, glutamate (e.g., NMDA receptor, AMPA receptor), GABA, acetylcholine, adenosine (e.g., A2A receptor), cannabinoid receptor, natriuretic peptide (e.g., ANP, BNP, CNP), endorphin intracellular signaling pathway and progesterone signaling pathway. For example, inhibition of PDE1B should act to potentiate the effect of a dopamine D1 agonist by protecting cGMP and cAMP from degradation, and should similarly inhibit dopamine D2 receptor signaling pathways, by inhibiting PDE1 activity. Chronic elevation in intracellular calcium levels is linked to cell death in numerous disorders, particularly in neurodegerative diseases such as Alzheimer's, Parkinson's and Huntington's Diseases and in disorders of the circulatory system leading to stroke and myocardial infarction. PDE1 inhibitors are therefore potentially useful in diseases characterized by reduced dopamine D1 receptor signaling activity, such as Parkinson's disease, restless leg syndrome, depression, narcolepsy and cognitive impairment. PDE1 inhibitors are also useful in diseases that may be alleviated by the enhancement of progesterone-signaling such as female sexual dysfunction.

There is thus a need for compounds that selectively inhibit PDE1 activity, especially PDE1A and/or PDE1B activity.

SUMMARY OF THE INVENTION

The invention provides optionally substituted 3-amino-(optionally 4-imino or 4-thioxo)-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6(7H)-ones and their 4-imino and 4-thioxo derivatives, e.g., 3-amino-4-(thioxo or imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, 3-amino-4-(thioxo or imino)-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones or 3-amino-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, preferably (optionally 1 or 2 and/or 5 and/or 7 substituted)-3-amino-(optionally 4-imino or 4-thioxo)-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6-ones, more preferably a compound of formula II:

wherein

(i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;

(ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);

(iii) R₂ is

-   -   H,     -   C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl or         2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with one or more halo (e.g., fluoro) or hydroxy         (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or         3-hydroxy-2-methylpropyl),     -   haloC₁₋₆alkyl (e.g., trifluoromethyl or 2,2,2-trifluoroethyl),     -   N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g., 2-(dimethylamino)ethyl or         2-aminopropyl),     -   arylC₀₋₆alkyl (e.g., phenyl or benzyl), wherein said aryl is         optionally substituted with one or more C₁₋₆alkoxy, for example,         C₁₋₆alkoxyarylC₀₋₆alkyl (e.g., 4-methoxybenzyl),     -   heteroarylC₀₋₆alkyl (e.g., pyridinylmethyl), wherein said         heteroaryl is optionally substituted with one or more C₁₋₆alkoxy         (e.g., C₁₋₆alkoxyheteroarylC₁₋₆alkyl);     -   -G-J wherein G is a single bond or C₁₋₆alkylene (e.g.,         methylene) and J is C₃₋₈cycloalkyl or heteroC₃₋₈cycloalkyl         (e.g., oxetan-2-yl, pyrrolidin-3-yl, pyrrolidin-2-yl) wherein         the cycloalkyl and heterocycloalkyl group are optionally         substituted with one or more C₁₋₆alkyl or amino, for example,         -   —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., —C₀₋₄alkyl-cyclopentyl,             —C₀₋₄alkyl-cyclohexyl or —C₀₋₄alkyl-cyclopropyl), wherein             said cycloalkyl is optionally substituted with one or more             C₁₋₆alkyl or amino (for example, 2-aminocyclopentyl or             2-aminocyclohexyl),         -   —C₀₋₄alkyl-C₃₋₈heterocycloalkyl (e.g.,             —C₀₋₄alkyl-pyrrolidinyl, for example,             —C₀₋₄alkylpyrrolidin-3-yl) wherein said heterocycloalkyl is             optionally substituted with C₁₋₆alkyl (e.g., methyl), for             example, 1-methylpyrrolidin-3-yl, 1-methyl-pyrrolindin-2-yl,             1-methyl-pyrrolindin-2-yl-methyl or             1-methyl-pyrrolindin-3-yl-methyl);

(iv) R₃ is

-   -   1) -D-E-F wherein:         -   D is a single bond, C₁₋₆alkylene (e.g., methylene), or             arylC₁₋₆alkylene (e.g., benzylene or —CH₂C₆H₄—);         -   E is             -   a single bond,             -   C₁₋₄alkylene (e.g., methylene, ethynylene,                 prop-2-yn-1-ylene),             -   C₀₋₄alkylarylene (e.g., phenylene or —C₆H₄—, -benzylene-                 or —CH₂C₆H₄—), wherein the arylene group is optionally                 substituted with halo (e.g., Cl or F),             -   heteroarylene (e.g., pyridinylene or pyrimidinylene),                 aminoC₁₋₆alkylene (e.g., —CH₂N(H)—),             -   amino (e.g., —N(H)—);             -   C₃₋₈cycloalkylene optionally containing one or more                 heteroatom selected from N or O (e.g., piperidinylene),         -   F is             -   H,             -   halo (e.g., F, Br, Cl),             -   C₁₋₆alkyl (e.g., isopropyl or isobutyl),             -   haloC₁₋₆alkyl (e.g., trifluoromethyl),             -   aryl (e.g., phenyl),             -   C₃₋₈cycloalkyl optionally containing one or more atom                 selected from a group consisting of N, S or O (e.g.,                 cyclopentyl, cyclohexyl, piperidinyl, pyrrolidinyl,                 tetrahydro-2H-pyran-4-yl, or morpholinyl), and                 optionally substituted with one or more C₁₋₆alkyl (e.g.,                 methyl or isopropyl), for example,                 1-methylpyrrolidin-2-yl, pyrrolidin-1-yl,                 pyrrolidin-2-yl, piperidin-2-yl, 1-methylpiperidin-2-yl,                 1-ethylpiperidin-2-yl,             -   heteroaryl (e.g., pyridyl (for example, pyrid-2-yl),                 pyrimidinyl (for example, pyrimidin-2-yl), thiadiazolyl                 (for example, 1,2,3-thiadiazol-4-yl), diazolyl (e.g.,                 pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for                 example, imidazol-1-yl, 4-methylimidazolyl,                 1-methylimidazol-2-yl)), triazolyl (e.g.,                 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl),                 alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol),                 wherein said heteroaryl is optionally substituted with                 one or more C₁₋₆alkyl, halo (e.g., fluoro) or                 haloC₁₋₆alkyl; C₁₋₆alkoxy,             -   —O-haloC₁₋₆alkyl (e.g., —O—CF₃),             -   C₁₋₆alkylsulfonyl (for example, methylsulfonyl or                 —S(O)₂CH₃),             -   —C(O)—R₁₃, wherein R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g.,                 methyl), —OC₁₋₆alkyl (e.g., —OCH₃),                 haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g., phenyl), or                 heteroaryl;             -   —N(R₁₄)(R₁₅);         -   or     -   2) a substituted heteroarylC₁₋₆alkyl, e.g., substituted with         haloC₁₋₆alkyl;         -   or     -   3) attached to one of the nitrogens on the pyrazolo portion of         Formula II and is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is                 -   halogen (e.g., fluoro or chloro),                 -   C₁₋₆alkyl,                 -   C₃₋₈cycloalkyl,                 -   heteroC₃₋₈cycloalkyl (e.g., pyrrolidinyl or                     piperidinyl),                 -   haloC₁₋₆alkyl (e.g., trifluoromethyl),                 -   aryl (e.g., phenyl) or heteroaryl (e.g., pyridyl,                     (for example, pyrid-2-yl) or e.g., thiadiazolyl (for                     example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl                     (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g.,                     tetrazol-5-yl), alkyloxadiazolyl (e.g.,                     5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g.,                     pyrazol-1-yl),                 -   wherein said aryl, heteroaryl, cycloalkyl or                     heterocycloalkyl is optionally substituted with one                     or more C₁₋₆alkyl (e.g., methyl), halogen (e.g.,                     chloro or fluoro), haloC₁₋₆alkyl (e.g.,                     trifluoromethyl), hydroxy, carboxy, —SH, or an                     additional aryl or heteroaryl (e.g., biphenyl or                     pyridylphenyl),                 -   C₁₋₆alkyl sulfonyl (e.g., methyl sulfonyl),                 -   arylcarbonyl (e.g., benzoyl),                 -   heteroarylcarbonyl,                 -   C₁₋₆alkoxycarbonyl, (e.g., methoxycarbonyl),                 -   Aminocarbonyl,                 -   —N(R₁₄)(R₁₅);                 -   preferably R₁₀ is phenyl, pyridyl, piperidinyl or                     pyrrolidinyl optionally substituted with the                     substituents previously defined, e.g. optionally                     substituted with halo or alkyl;             -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,                 respectively, is not present;

(v) R₄ and R₅ are independently:

-   -   H,     -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),     -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),     -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example         pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for example,         piperidin-1-yl), morpholinyl),     -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or     -   —C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or         pyrazol-3-yl)     -   wherein said aryl or heteroaryl is optionally substituted with         one or more halo (e.g., 4-fluorophenyl), hydroxy (e.g.,         4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group         (e.g., biphenyl-4-ylmethyl);

(vi) R₆ is H, C₁₋₆alkyl (e.g., methyl or ethyl) or C₃₋₈cycloalkyl;

(vii) R₁₄ and R is are independently H or C₁₋₆alkyl,

in free or salt form.

In a particular embodiment, the invention further provides compounds of Formula II as follows:

-   -   2.1 Formula II or 2.1, wherein Q is —C(═S)—, —C(═N(R₆))— or         —C(R₁₄)(R₁₅)—;     -   2.2 Formula II or 2.1, wherein Q is —C(═S)—;     -   2.3 Formula II or 2.1, wherein Q is —C(═N(R₆))—;     -   2.4 Formula II, wherein Q is —C(R₁₄)(R₁₅)—;     -   2.5 Formula II or any of 2.1-2.4, wherein R₁ is H or C₁₋₆alkyl         (e.g., methyl or ethyl);     -   2.6 Formula II or any of 2.1-2.5, wherein R₁ is H;     -   2.7 Formula II or any of 2.1-2.5, wherein R₁ is C₁₋₆alkyl (e.g.,         methyl or ethyl);     -   2.8 Formula II or any of 2.4-2.7, wherein R₂ is:         -   H,         -   C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl or             2,2-dimethylpropyl) wherein said alkyl group is optionally             substituted with one or more halo (e.g., fluoro) or hydroxy             (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or             3-hydroxy-2-methylpropyl),         -   haloC₁₋₆alkyl (e.g., trifluoromethyl or             2,2,2-trifluoroethyl),         -   N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g., 2-(dimethylamino)ethyl or             2-aminopropyl),         -   arylC₀₋₆alkyl (e.g., phenyl or benzyl), wherein said aryl is             optionally substituted with one or more C₁₋₆alkoxy, for             example, C₁₋₆alkoxyarylC₀₋₆alkyl (e.g., 4-methoxybenzyl),         -   heteroarylC₀₋₆alkyl (e.g., pyridinylmethyl), wherein said             heteroaryl is optionally substituted with one or more             C₁₋₆alkoxy (e.g., C₁₋₆alkoxyheteroarylC₁₋₆alkyl);         -   -G-J wherein G is a single bond or C₁₋₆alkylene (e.g.,             methylene) and J is C₃₋₈cycloalkyl or heteroC₃₋₈cycloalkyl             (e.g., oxetan-2-yl, pyrrolidin-3-yl, pyrrolidin-2-yl)             wherein the cycloalkyl and heterocycloalkyl group are             optionally substituted with one or more C₁₋₆alkyl or amino,             for example,             -   —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., —C₀₋₄alkyl-cyclopentyl,                 —C₀₋₄alkyl-cyclohexyl or —C₀₋₄alkyl-cyclopropyl),                 wherein said cycloalkyl is optionally substituted with                 one or more C₁₋₆alkyl or amino (for example,                 2-aminocyclopentyl or 2-aminocyclohexyl),             -   —C₀₋₄alkyl-C₃₋₈heterocycloalkyl (e.g.,                 —C₀₋₄alkyl-pyrrolidinyl, for example,                 —C₀₋₄alkylpyrrolidin-3-yl) wherein said heterocycloalkyl                 is optionally substituted with C₁₋₆alkyl (e.g., methyl),                 for example, 1-methylpyrrolidin-3-yl,                 1-methyl-pyrrolindin-2-yl,                 1-methyl-pyrrolindin-2-yl-methyl or                 1-methyl-pyrrolindin-3-yl-methyl);     -   2.9 Formula II or any of 2.4-2.8, wherein R₂ is:         -   C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl or             2,2-dimethylpropyl) wherein said alkyl group is optionally             substituted with one or more halo (e.g., fluoro) or hydroxy             (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or             3-hydroxy-2-methylpropyl),         -   haloC₁₋₆alkyl (e.g., trifluoromethyl or             2,2,2-trifluoroethyl),         -   N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g., 2-(dimethylamino)ethyl or             2-aminopropyl),         -   arylC₀₋₆alkyl (e.g., phenyl or benzyl), wherein said aryl is             optionally substituted with one or more C₁₋₆alkoxy, for             example, C₁₋₆alkoxyarylC₀₋₆alkyl (e.g., 4-methoxybenzyl),             heteroarylC₀₋₆alkyl (e.g., pyridinylmethyl), wherein said             heteroaryl is optionally substituted with one or more             C₁₋₆alkoxy (e.g., C₁₋₆alkoxyheteroarylC₁₋₆alkyl);         -   -G-J wherein G is a single bond or C₁₋₆alkylene (e.g.,             methylene) and J is C₃₋₈cycloalkyl or heteroC₃₋₈cycloalkyl             (e.g., oxetan-2-yl, pyrrolidin-3-yl, pyrrolidin-2-yl)             wherein the cycloalkyl and heterocycloalkyl group are             optionally substituted with one or more C₁₋₆alkyl or amino,             for example,         -   —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., —C₀₋₄alkyl-cyclopentyl,             —C₀₋₄alkyl-cyclohexyl or —C₀₋₄alkyl-cyclopropyl), wherein             said cycloalkyl is optionally substituted with one or more             C₁₋₆alkyl or amino (for example, 2-aminocyclopentyl or             2-aminocyclohexyl),         -   —C₀₋₄alkyl-C₃₋₈heterocycloalkyl (e.g.,             —C₀₋₄alkyl-pyrrolidinyl, for example,             —C₀₋₄alkylpyrrolidin-3-yl) wherein said heterocycloalkyl is             optionally substituted with C₁₋₆alkyl (e.g., methyl), for             example, 1-methylpyrrolidin-3-yl, 1-methyl-pyrrolindin-2-yl,             1-methyl-pyrrolindin-2-yl-methyl or             1-methyl-pyrrolindin-3-yl-methyl);     -   2.10 Formula II or any of 2.4-2.8, wherein R₂ is H,     -   2.11 Formula II or any of 2.4-2.9, wherein R₂ is C₁₋₆alkyl         (e.g., isopropyl, isobutyl, 2-methylbutyl or 2,2-dimethylpropyl)         wherein said alkyl group is optionally substituted with one or         more halo (e.g., fluoro) or hydroxy (e.g., hydroxyC₁₋₆alkyl, for         example 1-hydroxyprop-2-yl or 3-hydroxy-2-methylpropyl);     -   2.12 Formula II or any of 2.4-2.9, wherein R₂ is haloC₁₋₆alkyl         (e.g., trifluoromethyl or 2,2,2-trifluoroethyl);     -   2.13 Formula II or any of 2.4-2.9, wherein R₂ is         N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g.,         2-(dimethylamino)ethyl,2-aminopropyl);     -   2.14 Formula II or any of 2.4-2.9, wherein R₂ is arylC₀₋₆alkyl         (e.g., phenyl or benzyl), wherein said aryl is optionally         substituted with one or more C₁₋₆alkoxy, for example,         C₁₋₆alkoxyarylC₀₋₆alkyl (e.g., 4-methoxybenzyl);     -   2.15 Formula II or any of 2.4-2.9, wherein R₂ is         heteroarylC₀₋₆alkyl (e.g., pyridinylmethyl), wherein said         heteroaryl is optionally substituted with one or more C₁₋₆alkoxy         (e.g., C₁₋₆alkoxyheteroarylC₁₋₆alkyl);     -   2.16 Formula II or any of 2.4-2.9, wherein R₂ is -G-J wherein G         is a single bond or C₁₋₆alkylene (e.g., methylene) and J is         C₃₋₈cycloalkyl or heteroC₃₋₈cycloalkyl (e.g., oxetan-2-yl,         pyrrolidin-3-yl, pyrrolidin-2-yl) wherein the cycloalkyl and         heterocycloalkyl group are optionally substituted with one or         more C₁₋₆alkyl or amino, for example:         -   —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., —C₀₋₄alkyl-cyclopentyl,             —C₀₋₄alkyl-cyclohexyl or —C₀₋₄alkyl-cyclopropyl), wherein             said cycloalkyl is optionally substituted with one or more             C₁₋₆alkyl or amino (for example, 2-aminocyclopentyl or             2-aminocyclohexyl),         -   —C₀₋₄alkyl-C₃₋₈heterocycloalkyl (e.g.,             —C₀₋₄alkyl-pyrrolidinyl, for example,             —C₀₋₄alkylpyrrolidin-3-yl) wherein said heterocycloalkyl is             optionally substituted with C₁₋₆alkyl (e.g., methyl), for             example, 1-methylpyrrolidin-3-yl, 1-methyl-pyrrolindin-2-yl,             1-methyl-pyrrolindin-2-yl-methyl or             1-methyl-pyrrolindin-3-yl-methyl);     -   2.17 Formula II or any of 2.4-2.9, wherein R₂ is -G-J wherein G         is a single bond and J is C₃₋₈cycloalkyl or heteroC₃₋₈cycloalkyl         (e.g., oxetan-2-yl, pyrrolidin-3-yl, pyrrolidin-2-yl) wherein         the cycloalkyl and heterocycloalkyl group are optionally         substituted with one or more C₁₋₆alkyl or amino;     -   2.18 Formula II or any of 2.4-2.9, wherein R₂ is -G-J wherein G         is C₁₋₆alkylene (e.g., methylene) and J is C₃₋₈cycloalkyl or         heteroC₃₋₈cycloalkyl (e.g., oxetan-2-yl, pyrrolidin-3-yl,         pyrrolidin-2-yl) wherein the cycloalkyl and heterocycloalkyl         group are optionally substituted with one or more C₁₋₆alkyl or         amino;     -   2.19 Formula II or any of 2.4-2.9, wherein R₂ is         -   —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., —C₀₋₄alkyl-cyclopentyl,             —C₀₋₄alkyl-cyclohexyl or —C₀₋₄alkyl-cyclopropyl), wherein             said cycloalkyl is optionally substituted with one or more             C₁₋₆alkyl or amino (for example, 2-aminocyclopentyl or             2-aminocyclohexyl),         -   —C₀₋₄alkyl-C₃₋₈heterocycloalkyl (e.g.,             —C₀₋₄alkyl-pyrrolidinyl, for example,             —C₀₋₄alkylpyrrolidin-3-yl) wherein said heterocycloalkyl is             optionally substituted with C₁₋₆alkyl (e.g., methyl), for             example, 1-methylpyrrolidin-3-yl, 1-methyl-pyrrolindin-2-yl,             1-methyl-pyrrolindin-2-yl-methyl or             1-methyl-pyrrolindin-3-yl-methyl);     -   2.20 Formula II or any of 2.4-2.9, wherein R₂ is         2,2-dimethylpropyl;     -   2.21 Formula II or any of 2.4-2.9, wherein R₂ is isobutyl;     -   2.22 Formula II or any of 2.4-2.9, wherein R₂ is         1-hydroxyprop-2-yl or 3-hydroxy-2-methylpropyl;     -   2.23 Formula II or any of 2.4-2.9, wherein R₂ is cyclopentyl;     -   2.24 Formula II or any of 2.4-2.9, wherein R₂ is         —C₀₋₄alkyl-pyrrolidinyl wherein the pyrrolidinyl is optionally         substituted with one or more C₁₋₆alkyl, e.g.,         1-methylpyrrolidin-3-yl, 1-methyl-pyrrolindin-2-yl,         1-methyl-pyrrolindin-2-yl-methyl or         1-methyl-pyrrolindin-3-yl-methyl);     -   2.25 Formula II or any of 2.4-2.24, wherein R₃ is -D-E-F         wherein:         -   D is             -   a single bond,             -   C₁₋₆alkylene (e.g., methylene), or             -   arylC₁₋₆alkylene (e.g., benzylene or —CH₂C₆H₄—);         -   E is             -   a single bond,             -   C₁₋₄alkylene (e.g., methylene, ethynylene,                 prop-2-yn-1-ylene),             -   C₀₋₄alkylarylene (e.g., phenylene or —C₆H₄—, -benzylene-                 or —CH₂C₆H₄—), wherein the arylene group is optionally                 substituted with halo (e.g., Cl or F),             -   heteroarylene (e.g., pyridinylene or pyrimidinylene),             -   aminoC₁₋₆alkylene (e.g., —CH₂—N(H)—),             -   amino (e.g., —N(H)—);             -   C₃₋₈cycloalkylene optionally containing one or more                 heteroatom selected from N, S or O (e.g.,                 piperidinylene),         -   F is             -   H,             -   halo (e.g., F, Br, Cl),             -   C₁₋₆alkyl (e.g., isopropyl or isobutyl),             -   haloC₁₋₆alkyl (e.g., trifluoromethyl),             -   aryl (e.g., phenyl),             -   C₃₋₈cycloalkyl optionally containing one or more atom                 selected from a group consisting of N, S or O (e.g.,                 cyclopentyl, cyclohexyl, piperidinyl, pyrrolidinyl,                 tetrahydro-2H-pyran-4-yl, or morpholinyl), and                 optionally substituted with one or more C₁₋₆alkyl (e.g.,                 methyl or isopropyl), for example,                 1-methylpyrrolidin-2-yl, pyrrolidin-1-yl,                 pyrrolidin-2-yl, piperidin-2-yl, 1-methylpiperidin-2-yl,                 1-ethylpiperidin-2-yl,             -   heteroaryl (e.g., pyridyl (for example, pyrid-2-yl),                 pyrimidinyl (for example, pyrimidin-2-yl), thiadiazolyl                 (for example, 1,2,3-thiadiazol-4-yl), diazolyl (e.g.,                 pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for                 example, imidazol-1-yl, 4-methylimidazolyl,                 1-methylimidazol-2-yl)), triazolyl (e.g.,                 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl),                 alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol),                 wherein said heteroaryl is optionally substituted with                 one or more C₁₋₆alkyl, halo (e.g., fluoro) or                 haloC₁₋₆alkyl;             -   C₁₋₆alkoxy,             -   —O-haloC₁₋₆alkyl (e.g., —O—CF₃),             -   C₁₋₆alkylsulfonyl (for example, methylsulfonyl or                 S(O)₂CH₃),             -   —C(O)—R₁₃, wherein R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g.,                 methyl), —OC₁₋₆alkyl (e.g., —OCH₃),                 haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g., phenyl), or                 heteroaryl,             -   —N(R₁₄)(R₁₅);     -   2.26 Formula 2.25, wherein R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g.,         methyl), —OC₁₋₆alkyl (e.g., —OCH₃),         haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g., phenyl), or         heteroaryl;     -   2.27 Formula 2.25, wherein D is C₁₋₆alkylene (e.g., methylene),         E is C₃₋₈cycloalkylene optionally containing one or more         heteroatom selected from N, S or O (e.g., piperidinylene) and F         is C₁₋₆alkyl (e.g., isopropyl or isobutyl), for example, R₃ is         isopropylpiperidin-1-ylmethyl;     -   2.28 Formula II or any of 2.4-2.24, wherein R₃ is a substituted         heteroarylC₀₋₆alkyl, e.g., substituted with haloC₁₋₆alkyl, for         example;     -   2.29 Formula II or any of 2.4-2.24, wherein R₃ is attached to         one of the nitrogens on the pyrazolo portion of Formula II and         is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is                 -   halogen (e.g., fluoro or chloro),                 -   C₁₋₆alkyl,                 -   C₃₋₈cycloalkyl,                 -   heteroC₃₋₈cycloalkyl (e.g., pyrrolidinyl or                     piperidinyl),                 -   haloC₁₋₆alkyl (e.g., trifluoromethyl),                 -   aryl (e.g., phenyl) or heteroaryl (e.g., pyridyl,                     (for example, pyrid-2-yl) or e.g., thiadiazolyl (for                     example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl                     (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g.,                     tetrazol-5-yl), alkyloxadiazolyl (e.g.,                     5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g.,                     pyrazol-1-yl),                 -   wherein said aryl, heteroaryl, cycloalkyl or                     heterocycloalkyl is optionally substituted with one                     or more C₁₋₆alkyl (e.g., methyl), halogen (e.g.,                     chloro or fluoro), haloC₁₋₆alkyl (e.g.,                     trifluoromethyl), hydroxy, carboxy, —SH or an                     additional aryl or heteroaryl (e.g., biphenyl or                     pyridylphenyl)                 -   C₁₋₆alkyl sulfonyl (e.g., methyl sulfonyl),                 -   arylcarbonyl (e.g., benzoyl),                 -   heteroarylcarbonyl,                 -   C₁₋₆alkoxycarbonyl, (e.g., methoxycarbonyl),                     aminocarbonyl                 -   —N(R₁₄)(R₁₅);             -   preferably R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl,                 optionally substituted with one or more C₁₋₆alkyl (e.g.,                 methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl                 (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an                 additional aryl or heteroaryl (e.g., biphenyl or                 pyridylphenyl);             -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,                 respectively, is not present;

    -   2.30 Formula 2.29, wherein X, Y and/or Z are independently         nitrogen and R₈, R₉, R₁₁ and R₁₂ are H provided that when X, Y         or Z are nitrogen, R₈, R₉ and R₁₀, respectively, are not         present;

    -   2.31 Formula 2.29, wherein R₃ is X, Y and Z are C, R₈, R₉, R₁₁         and R₁₂ are H,

    -   2.32 Formulae 2.29, 2.30 or 2.31, wherein R₁₀ is         -   halogen (e.g., fluoro or chloro),         -   C₁₋₆alkyl,         -   C₃₋₈cycloalkyl,         -   heteroC₃₋₈cycloalkyl (e.g., pyrrolidinyl or piperidinyl),         -   haloC₁₋₆alkyl (e.g., trifluoromethyl),         -   aryl (e.g., phenyl) or heteroaryl (e.g., pyridyl, (for             example, pyrid-2-yl) or e.g., thiadiazolyl (for example,             1,2,3-thiadiazol-4-yl), diazolyl, triazolyl (e.g.,             1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl),             alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), pyrazolyl             (e.g., pyrazol-1-yl),         -   wherein said aryl, heteroaryl, cycloalkyl or             heterocycloalkyl is optionally substituted with one or more             C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro),             haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH             or an additional aryl or heteroaryl (e.g., biphenyl or             pyridylphenyl),         -   C₁₋₆alkyl sulfonyl (e.g., methyl sulfonyl),         -   arylcarbonyl (e.g., benzoyl),         -   heteroarylcarbonyl,         -   C₁₋₆alkoxycarbonyl, (e.g., methoxycarbonyl),         -   aminocarbonyl,         -   —N(R₁₄)(R₁₅);

    -   2.33 Any of formulae 2.29-2.32, wherein R₁₀ is halogen (e.g.,         fluoro or chloro);

    -   2.34 Any of formulae 2.29-2.32, wherein R₁₀ is haloC₁₋₆alkyl         (e.g., trifluoromethyl);

    -   2.35 Any of formulae 2.29-2.32, wherein R₁₀ is C₃₋₈cycloalkyl;

    -   2.36 Any of formulae 2.29-2.32, wherein R₁₀ is C₁₋₆alkyl         sulfonyl (e.g., methyl sulfonyl);

    -   2.37 Any of formulae 2.29-2.32, wherein R₁₀ is arylcarbonyl         (e.g., benzoyl);

    -   2.38 Any of formulae 2.29-2.32, wherein R₁₀ is         heteroarylcarbonyl;

    -   2.39 Any of formulae 2.29-2.32, wherein R₁₀ is         C₁₋₆alkoxycarbonyl, (e.g., methoxycarbonyl);

    -   2.40 Any of formulae 2.29-2.32, wherein R₁₀ is aminocarbonyl;

    -   2.41 Any of formulae 2.29-2.32, wherein R₁₀ is aryl (e.g.,         phenyl), wherein said aryl is optionally substituted with one or         more C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro),         haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH or         an additional aryl or heteroaryl (e.g., biphenyl);

    -   2.42 Any of formulae 2.29-2.32, wherein R₁₀ is heteroaryl (e.g.,         pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl (for         example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl (e.g.,         1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl),         alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), pyrazolyl         (e.g., pyrazol-1-yl), wherein said heteroaryl is optionally         substituted with one or more C₁₋₆alkyl (e.g., methyl), halogen         (e.g., chloro or fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl),         hydroxy, carboxy, —SH or an additional aryl or heteroaryl (e.g.,         biphenyl or pyridylphenyl);

    -   2.43 Any of formulae 2.29-2.33, wherein R₁₀ is triazolyl (e.g.,         1,2,4-triazol-1-yl);

    -   2.44 Any of formulae 2.29-2.33, wherein R₁₀ is pyridyl (e.g.,         pyrid-2-yl);

    -   2.45 Any of formulae 2.29-2.32, wherein R₁₀ is —N(R₁₄)(R₁₅);

    -   2.46 Formula II or any of 2.1-2.45, wherein R₄ and R₅ are         independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example             pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for             example, piperidin-1-yl), morpholinyl),         -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or             C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or             pyrazol-3-yl) wherein said aryl or heteroaryl is optionally             substituted with one or more halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   2.47 Formula II or any of 2.1-2.46, wherein R₄ and R₅ as         described in Formula II above.

    -   2.48 Formula 2.47, wherein R₄ or R₅ is H,

    -   2.49 Formula 2.47 or 2.48, wherein R₄ or R₅ is C₁₋₆alkyl (e.g.,         methyl, isopropyl, isobutyl, n-propyl);

    -   2.50 Any of formulae 2.47-2.49, wherein either R₄ or R₅ is         C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl);

    -   2.51 Any of formulae 2.47-2.50, wherein either R₄ or R₅ is         C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example         pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for example,         piperidin-1-yl), morpholinyl);

    -   2.52 Any of formulae 2.47-2.51, wherein either R₄ or R₅ is         —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or —C₀₋₆alkylheteroaryl         (e.g., pyrid-4-yl, pyrid-2-yl or pyrazol-3-yl) wherein said aryl         or heteroaryl is optionally substituted with one or more halo         (e.g., 4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl),         C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group (e.g.,         biphenyl-4-ylmethyl);

    -   2.53 Formula 2.47, wherein R₄ or R₅ is H or C₁₋₆alkyl (e.g.,         methyl, isopropyl, isobutyl, n-propyl), and the other is         -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example             pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for             example, piperidin-1-yl), morpholinyl),         -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or             —C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or             pyrazol-3-yl) wherein said aryl or heteroaryl is optionally             substituted with one or more halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   2.54 Any of formulae 2.47-2.53, wherein either R₄ or R₅ is         phenyl optionally substituted with one or more halo (e.g.,         4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl,         C₁₋₆alkoxy or another aryl group (e.g., biphenyl-4-ylmethyl);

    -   2.55 Any of formulae 2.47-2.53, wherein either R₄ or R₅ is         4-fluorophenyl;

    -   2.56 Any of formulae 2.47-2.53, wherein either R₄ or R₅ is         4-hydroxyphenyl;

    -   2.57 Any of formulae 2.47-2.53, wherein either R₄ or R₅ is         C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),

    -   2.58 Any of formulae 2.47-2.53, wherein either R₄ is H and R₅ is         phenyl optionally substituted with one or more halo (e.g.,         4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl,         C₁₋₆alkoxy or another aryl group (e.g., biphenyl-4-ylmethyl);

    -   2.59 Any of the preceding formulae wherein R₆ is H, C₁₋₆alkyl         (e.g., methyl or ethyl) or C₃₋₈cycloalkyl;

    -   2.60 Any of the preceding formulae wherein R₆ is C₃₋₈cycloalkyl;

    -   2.61 Any of the preceding formulae wherein R₆ is H,

    -   2.62 Any of the preceding formulae wherein R₆ is C₁₋₆alkyl         (e.g., methyl or ethyl);

    -   2.63 Any of the preceding formulae wherein the compound is         selected from any of the following:

-   -   2.64 Any of formulae 2.1-2.62, wherein the compound is selected         from any of the following:

-   -   2.65 Any of formulae 2.1-2.62, wherein the compound is selected         from any of the following:

-   -   2.66 any of the preceding formulae wherein the compounds inhibit         phosphodiesterase-mediated (e.g., PDE1-mediated, especially

PDE1B-mediated) hydrolysis of cGMP, e.g., with an IC₅₀ of less than 1 μM, preferably less than 500 nM, preferably less than 200 nM in an immobilized-metal affinity particle reagent PDE assay, for example, as described in Example 5;

In another aspect, the Compound of the Invention is a Compound of Formula II, wherein

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);     -   (iii) R₂ is C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl         or 2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with one or more halo (e.g., fluoro) or hydroxy         (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or         3-hydroxy-2-methylpropyl),     -   (iv) R₃ is attached to one of the nitrogens on the pyrazolo         portion of Formula II and is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is                 -   halogen (e.g., fluoro or chloro),                 -   C₁₋₆alkyl,                 -   C₃₋₈cycloalkyl,                 -   heteroC₃₋₈cycloalkyl (e.g., pyrrolidinyl or                     piperidinyl),                 -   haloC₁₋₆alkyl (e.g., trifluoromethyl),                 -   aryl (e.g., phenyl) or heteroaryl (e.g., pyridyl,                     (for example, pyrid-2-yl) or e.g., thiadiazolyl (for                     example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl                     (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g.,                     tetrazol-5-yl), alkyloxadiazolyl (e.g.,                     5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g.,                     pyrazol-1-yl),                 -   wherein said aryl, heteroaryl, cycloalkyl or                     heterocycloalkyl is optionally substituted with one                     or more C₁₋₆alkyl (e.g., methyl), halogen (e.g.,                     chloro or fluoro), haloC₁₋₆alkyl (e.g.,                     trifluoromethyl), hydroxy, carboxy, —SH or an                     additional aryl or heteroaryl (e.g., biphenyl or                     pyridylphenyl)                 -   C₁₋₆alkyl sulfonyl (e.g., methyl sulfonyl),                 -   arylcarbonyl (e.g., benzoyl),                 -   heteroarylcarbonyl,                 -   C₁₋₆alkoxycarbonyl, (e.g., methoxycarbonyl),                 -   Aminocarbonyl,                 -   —N(R₁₄)(R₁₅);                 -   preferably R₁₀ is phenyl or pyridyl, e.g.,                     2-pyridyl, optionally substituted with one or more                     C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or                     fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl),                     hydroxy, carboxy, —SH or an additional aryl or                     heteroaryl (e.g., biphenyl or pyridylphenyl);             -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,                 respectively, is not present;

    -   (v) R₄ and R₅ are independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example             pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for             example, piperidin-1-yl), morpholinyl),         -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or             —C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or             pyrazol-3-yl) wherein said aryl or heteroaryl is optionally             substituted with one or more halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₆₋alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl or ethyl) or         C₃₋₈cycloalkyl;

    -   (vii) R₁₄ and R₁₅ are independently H or C₁₋₆alkyl,         in free or salt form (hereinafter, Formula II(a)).

In another aspect, the Compound of the Invention is a Compound of Formula II, wherein:

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);     -   (iii) R₂ is C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl         or 2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with one or more halo (e.g., fluoro) or hydroxy         (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or         3-hydroxy-2-methylpropyl),     -   (iv) R₃ is attached to one of the nitrogens on the pyrazolo         portion of Formula II and is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl, or                 pyrrolidinyl optionally substituted with one or more                 C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or                 fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy,                 carboxy, —SH or an additional aryl or heteroaryl (e.g.,                 biphenyl or pyridylphenyl);             -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,                 respectively, is not present;

    -   (v) R₄ and R₅ are independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example             pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for             example, piperidin-1-yl), morpholinyl),         -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or             C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or             pyrazol-3-yl) wherein said aryl or heteroaryl is optionally             substituted with one or more halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl or ethyl) or         C₃₋₈cycloalkyl;

    -   (vii) R₁₄ and R₁₅ is are independently H or C₁₋₆alkyl,         in free or salt form (hereinafter, Formula II(b)).

In another aspect, the Compound of the Invention is a Compound of Formula II wherein:

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);     -   (iii) R₂ is C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl         or 2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with one or more halo (e.g., fluoro) or hydroxy         (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or         3-hydroxy-2-methylpropyl),     -   (iv) R₃ is attached to one of the nitrogens on the pyrazolo         portion of Formula II and is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl, pyrrolidinyl                 optionally substituted with one or more C₁₋₆alkyl (e.g.,                 methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl                 (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an                 additional aryl or heteroaryl (e.g., biphenyl or                 pyridylphenyl);             -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,                 respectively, is not present;

    -   (v) R₄ and R₅ are independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example             pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for             example, piperidin-1-yl), morpholinyl),         -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or             —C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or             pyrazol-3-yl) wherein said aryl or heteroaryl is optionally             substituted with one or more halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   (vi) R₆ is H or C₁₋₆alkyl (e.g., methyl or ethyl);

    -   (vii) R₁₄ and R₁₅ are independently H or C₁₋₆alkyl,         in free or salt form (hereinafter, Formula II(c)).

In another aspect, the Compound of the Invention is a Compound of Formula II wherein:

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);     -   (iii) R₂ is C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl         or 2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with one or more halo (e.g., fluoro) or hydroxy         (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or         3-hydroxy-2-methylpropyl),     -   (iv) R₃ is attached to one of the nitrogens on the pyrazolo         portion of Formula-II and is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl, pyrrolidinyl                 optionally substituted with one or more C₁₋₆alkyl (e.g.,                 methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl                 (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an                 additional aryl or heteroaryl (e.g., biphenyl or                 pyridylphenyl);         -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,             respectively, is not present;

    -   (v) R₄ is H and R₅ is:         -   H,         -   C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example             pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for             example, piperidin-1-yl), morpholinyl),         -   —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or             —C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or             pyrazol-3-yl) wherein said aryl or heteroaryl is optionally             substituted with one or more halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl or ethyl);

    -   (vii) R₁₄ and R is are independently H or C₁₋₆alkyl,         in free or salt form (hereinafter, Formula II(d)).

In another aspect, the Compound of the Invention is a Compound of Formula II, wherein:

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);     -   (iii) R₂ is C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl         or 2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with one or more halo (e.g., fluoro) or hydroxy         (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or         3-hydroxy-2-methylpropyl),     -   (iv) R₃ is attached to one of the nitrogens on the pyrazolo         portion of Formula II and is a moiety of Formula A

-   -   -   wherein:             -   X, Y and Z are, independently, N or C,             -   R₈, R₉, R₁₁ and R₁₂ are independently H or halogen                 (e.g., Cl or F); and             -   R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl, or                 pyrrolidinyl optionally substituted with one or more                 C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or                 fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy,                 carboxy, —SH or an additional aryl or heteroaryl (e.g.,                 biphenyl or pyridylphenyl);             -   provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀,                 respectively, is not present;

    -   (v) R₄ is H and R₅ phenyl optionally substituted with one or         more halo (e.g., 4-fluorophenyl), hydroxy (e.g.,         4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group         (e.g., biphenyl-4-ylmethyl);

    -   (vi) R₆ is H or C₁₋₆alkyl (e.g., methyl or ethyl);

    -   (vii) R₁₄ and R is are independently H or C₁₋₆alkyl,         in free or salt form (hereinafter, Formula II(e)).

In another aspect, the Compound of the Invention is a Compound of Formula I:

wherein

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl);     -   (iii) R₂ is         -   H,         -   C₁₋₆alkyl (e.g., isopropyl, isobutyl, neopentyl,             2-methylbutyl, 2,2-dimethylpropyl) wherein said alkyl group             is optionally substituted with halo (e.g., fluoro) or             hydroxy (e.g., 1-hydroxypropan-2-yl,             3-hydroxy-2-methylpropyl),         -   —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., cyclopentyl, cyclohexyl)             optionally substituted with one or more amino (e.g., —NH₂),             for example, 2-aminocyclopentyl or 2-aminocyclohexyl),             wherein said cycloalkyl optionally contains one or more             heteroatom selected from N and O and is optionally             substituted with C₁₋₆alkyl (e.g., 1-methyl-pyrrolindin-2-yl,             1-methyl-pyrrolindin-3-yl, 1-methyl-pyrrolindin-2-yl-methyl             or 1-methyl-pyrrolindin-3-yl-methyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl, for example,             pyrrolidin-3-yl) optionally substituted with C₁₋₆alkyl             (e.g., methyl), for example, 1-methylpyrrolidin-3-yl,         -   C₃₋₈cycloalkyl-C₁₋₆alkyl (e.g., cyclopropylmethyl),         -   haloC₁₋₆alkyl (e.g., trifluoromethyl, 2,2,2-trifluoroethyl),         -   —N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g.,             2-(dimethylamino)ethyl,2-aminopropyl),         -   hydroxyC₁₋₆alkyl (e.g., (e.g., 3-hydroxy-2-methylpropyl,             1-hydroxyprop-2-yl),         -   arylC₀₋₆alkyl (e.g., benzyl),         -   heteroarylC₁₋₆alkyl (e.g., pyridinylmethyl),         -   C₁₋₆alkoxyarylC₁₋₆alkyl (e.g., 4-methoxybenzyl);         -   -G-J wherein:             -   G is a single bond or, alkylene (e.g., methylene);             -   J is cycloalkyl or heterocycloalkyl (e.g., oxetan-2-yl,                 pyrolyin-3-yl, pyrolyin-2-yl) optionally substituted                 with C₁₋₆alkyl (e.g., (1-methylpyrrolidin-2-yl));     -   (iv) R₃ is         -   1) -D-E-F wherein:             -   D is a single bond, C₁₋₆alkylene (e.g., methylene), or                 arylalkylene (e.g., benzylene or —CH₂C₆H₄—);             -   E is                 -   a single bond,                 -   C₁₋₄alkylene (e.g., methylene, ethynylene,                     prop-2-yn-1-ylene),                 -   —C₀₋₄alkylarylene (e.g., phenylene or —C₆H₄—,                     -benzylene- or —CH₂C₆H₄—), wherein the arylene group                     is optionally substituted with halo (e.g., Cl or F),                 -   heteroarylene (e.g., pyridinylene or                     pyrimidinylene),                 -   aminoC₁₋₆alkylene (e.g., —CH₂—N(H)—),                 -   amino (e.g., —N(H)—);                 -   C₃₋₈cycloalkylene optionally containing one or more                     heteroatom selected from N or O (e.g.,                     piperidinylene),             -   F is                 -   H,                 -   halo (e.g., F, Br, Cl),                 -   C₁₋₆alkyl (e.g., isopropyl or isobutyl),                 -   haloC₁₋₆alkyl (e.g., trifluoromethyl),                 -   aryl (e.g., phenyl),                 -   C₃₋₈cycloalkyl optionally containing at least one                     atom selected from a group consisting of N or O                     (e.g., cyclopentyl, cyclohexyl, piperidinyl,                     pyrrolidinyl, tetrahydro-2H-pyran-4-yl, or                     morpholinyl), and optionally substituted with                     C₁₋₆alkyl (e.g., methyl or isopropyl), for example,                     1-methylpyrrolidin-2-yl, pyrrolidin-1-yl,                     pyrrolidin-2-yl, piperidin-2-yl,                     1-methylpiperidin-2-yl, 1-ethylpiperidin-2-yl,                 -   heteroaryl optionally substituted with C₁₋₆alkyl,                     (e.g., pyridyl, (for example, pyrid-2-yl),                     pyrimidinyl (for example, pyrimidin-2-yl),                     thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl),                     diazolyl (e.g., pyrazolyl (for example,                     pyrazol-1-yl) or imidazolyl (for example,                     imidazol-1-yl, 4-methylimidazolyl,                     1-methylimidazol-2-yl), triazolyl (e.g.,                     1,2,4-triazol-1-yl), tetrazolyl (e.g.,                     tetrazol-5-yl), alkoxadiazolyl (e.g.,                     5-methyl-1,2,4-oxadiazol), wherein said heteroaryl                     is optionally substituted with halo (e.g., fluoro)                     or haloC₁₋₆alkyl;                 -   amino (e.g., —NH₂),                 -   C₁₋₆alkoxy,                 -   —O-haloC₁₋₆alkyl (e.g., —O—CF₃),                 -   C₁₋₆alkylsulfonyl (for example, methylsulfonyl or                     —S(O)₂CH₃),                 -   —C(O)—R₁₃,                 -   —N(R₁₄)(R₁₅); or     -   2) a substituted heteroarylaklyl, e.g., substituted with         haloalkyl; or     -   3) attached to one of the nitrogens on the pyrazolo portion of         Formula I and is a moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F);             and R₁₀ is halogen, alkyl, cycloalkyl, haloalkyl (e.g.,             trifluoromethyl), aryl (e.g., phenyl), heteroaryl (e.g.,             pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl             (for example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl             (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g.,             tetrazol-5-yl), alkoxadiazolyl (e.g.,             5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl),             alkyl sulfonyl (e.g., methyl sulfonyl), arylcarbonyl (e.g.,             benzoyl), or heteroarylcarbonyl, alkoxycarbonyl, (e.g.,             methoxycarbonyl), aminocarbonyl; preferably phenyl or             pyridyl, e.g., 2-pyridyl; provided that when X, Y or X is             nitrogen, R₈, R₉ or R₁₀, respectively, is not present;

    -   (v) R₄ and R₅ are independently         -   H,         -   C₁₋₆alkyl (e.g., methyl, isopropyl),         -   C₃₋₈cycloalkyl (e.g., cyclopentyl),         -   C₃₋₈heterocycloalkyl (e.g., pyrrolidin-3-yl),         -   aryl (e.g., phenyl) or heteroaryl (e.g., pyrid-4-yl,             pyrid-2-yl or pyrazol-3-yl) wherein said aryl or heteroaryl             is optionally substituted with halo (e.g., 4-fluorophenyl),             hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or             another aryl group (e.g., biphenyl-4-ylmethyl);

    -   (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl) or C₃₋₈cycloalkyl;

    -   (vii) R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g., methyl), —OC₁₋₆alkyl         (e.g., —OCH₃), haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g.,         phenyl), or heteroaryl; and

    -   (viii) R₁₄ and R₁₅ are independently H or C₁₋₆alkyl, in free,         salt or prodrug form.

The invention further provides compounds of Formula I as follows:

-   -   1.1 Formula I, wherein Q is C(═S)—;     -   1.2 Formula I, wherein Q is C(═N(R₆))—;     -   1.3 Formula I, wherein Q is —C(R₁₄)(R₁₅)—;     -   1.4 Formula I, or any of 1.1-1.3, wherein R₃ is -D-E-F;     -   1.5 Formula 1.4, D is a single bond, C₁₋₆alkylene (e.g.,         methylene), or arylalkylene (e.g., benzylene or —CH₂C₆H₄—);     -   1.6 Formula 1.4, wherein D is a single bond;     -   1.7 Formula 1.4, wherein D is C₁₋₆alkylene (e.g., methylene);     -   1.8 Formula 1.4, wherein D is methylene;     -   1.9 Formula 1.4, wherein D is arylalkylene (e.g., benzylene or         —CH₂C₆H₄—);     -   1.10 Formula 1.4, wherein D is benzylene or —CH₂C₆H₄—;     -   1.11 Any of formulae 1.4-1.10, wherein E is a single bond,         C₁₋₄alkylene (e.g., methylene, ethynylene, prop-2-yn-1-ylene),         —C₀₋₄alkylarylene (e.g., phenylene or —C₆H₄—, -benzylene- or         —CH₂C₆H₄—), wherein the arylene group is optionally substituted         with halo (e.g., Cl or F); heteroarylene (e.g., pyridinylene or         pyrimidinylene), aminoC₁₋₆alkylene (e.g., —CH₂—N(H)—), amino         (e.g., —N(H)—), C₃₋₈cycloalkylene optionally containing one or         more heteroatom selected from N or O (e.g., piperidinylene);     -   1.12 Any of formulae 1.4-1.10, wherein E is a single bond;     -   1.13 Any of formulae 1.4-1.10, wherein E is C₁₋₄alkylene (e.g.,         methylene, ethynylene, prop-2-yn-1-ylene);     -   1.14 Any of formulae 1.4-1.10, wherein E is methylene;     -   1.15 Any of formulae 1.4-1.10, wherein E is ethynylene;     -   1.16 Any of formulae 1.4-1.10, wherein E is prop-2-yn-1-ylene;     -   1.17 Any of formulae 1.4-1.10, wherein E is —C₀₋₄alkylarylene         (e.g., phenylene or —C₆H₄—, -benzylene- or —CH₂C₆H₄—), wherein         the arylene group is optionally substituted with halo (e.g., Cl         or F);     -   1.18 Any of formulae 1.4-1.10, wherein E is phenylene or —C₆H₄—;     -   1.19 Any of formulae 1.4-1.10, wherein E is heteroarylene (e.g.,         pyridinylene or pyrimidinylene);     -   1.20 Any of formulae 1.4-1.10, wherein E is pyridinylene;     -   1.21 Any of formulae 1.4-1.10, wherein E is pyrimidinylene;     -   1.22 Any of formulae 1.4-1.10, wherein E is aminoC₁₋₆alkylene         (e.g., —CH₂—N(H)—);     -   1.23 Any of formulae 1.4-1.10, wherein E is amino (e.g.,         —N(H)—);     -   1.24 Any of formulae 1.4-1.10, wherein E is C₃₋₈cycloalkylene         optionally containing one or more heteroatom selected from N or         O (e.g., piperidinylene);     -   1.25 Any of formulae 1.4-1.24, wherein F is H, halo (e.g., F,         Br, Cl), C₁₋₆alkyl (e.g., isopropyl or isobutyl), haloC₁₋₆alkyl         (e.g., trifluoromethyl), aryl (e.g., phenyl), C₃₋₈cycloalkyl         optionally containing at least one atom selected from a group         consisting of N or O (e.g., cyclopentyl, cyclohexyl,         piperidinyl, pyrrolidinyl, tetrahydro-2H-pyran-4-yl, or         morpholinyl), and optionally substituted with C₁₋₆alkyl (e.g.,         methyl or isopropyl), for example, 1-methylpyrrolidin-2-yl,         pyrrolidin-1-yl, pyrrolidin-2-yl, piperidin-2-yl,         1-methylpiperidin-2-yl, 1-ethylpiperidin-2-yl; heteroaryl         optionally substituted with C₁₋₆alkyl (e.g., pyridyl, (for         example, pyrid-2-yl), pyrimidinyl (for example, pyrimidin-2-yl),         thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl         (e.g., pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for         example, imidazol-1-yl, 4-methylimidazolyl,         1-methylimidazol-2-yl), triazolyl (e.g., 1,2,4-triazol-1-yl),         tetrazolyl (e.g., tetrazol-5-yl), alkoxadiazolyl (e.g.,         5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl), amino         (e.g., —NH₂), C₁₋₆alkoxy, O-haloC₁₋₆alkyl (e.g., O—CF₃),         C₁₋₆alkylsulfonyl (for example, methylsulfonyl or S(O)₂CH₃),         C(O)—R₁₃ or —N(R₁₄)(R₁₅);     -   1.26 Any of formulae 1.4-1.25, wherein F is H;

1.27 Any of formulae 1.4-1.25, wherein F is halo (e.g., F, Br, Cl);

-   -   1.28 Any of formulae 1.4-1.25, wherein F is fluoro;     -   1.29 Any of formulae 1.4-1.25, wherein F is C₁₋₆alkyl (e.g.,         isopropyl or isobutyl);     -   1.30 Any of formulae 1.4-1.25, wherein F is isopropyl;     -   1.31 Any of formulae 1.4-1.25, wherein F is isobutyl;     -   1.32 Any of formulae 1.4-1.25, wherein F is haloC₁₋₆alkyl (e.g.,         trifluoromethyl);     -   1.33 Any of formulae 1.4-1.25, wherein F is trifluoromethyl;     -   1.34 Any of formulae 1.4-1.25, wherein F is aryl (e.g., phenyl);     -   1.35 Any of formulae 1.4-1.25, wherein F is phenyl;     -   1.36 Any of formulae 1.4-1.25, wherein F is C₃₋₈cycloalkyl         optionally containing at least one atom selected from a group         consisting of N or O (e.g., cyclopentyl, cyclohexyl,         piperidinyl, pyrrolidinyl tetrahydro-2H-pyran-4-yl,         morpholinyl); and optionally substituted with C₁₋₆alkyl (e.g.,         methyl or isopropyl), for example, 1-methylpyrrolidin-2-yl), for         example, 1-methylpyrrolidin-2-yl, pyrrolidin-1-yl,         pyrrolidin-2-yl, piperidin-2-yl, 1-methylpiperidin-2-yl,         1-ethylpiperidin-2-yl;     -   1.37 Any of formulae 1.4-1.25, wherein F is cyclopentyl or         cyclohexyl;     -   1.38 Any of formulae 1.4-1.25, wherein F is         1-methylpyrrolidin-2-yl;     -   1.39 Any of formulae 1.4-1.25, wherein F is heteroaryl         optionally substituted with C₁₋₆alkyl (e.g., pyridyl, (for         example, pyrid-2-yl), pyrimidinyl (for example, pyrimidin-2-yl),         thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl         (e.g., pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for         example, imidazol-1-yl, 4-methylimidazolyl,         1-methylimidazol-2-yl), triazolyl (e.g., 1,2,4-triazol-1-yl),         tetrazolyl (e.g., tetrazol-5-yl), alkoxadiazolyl (e.g.,         5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl),         wherein said heteroaryl is optionally substituted with halo         (e.g., fluoro) or haloC₁₋₆alkyl;     -   1.40 Any of formulae 1.4-1.25, wherein F is pyrid-2-yl         optionally substituted with halo (e.g., fluoro);     -   1.41 Any of formulae 1.4-1.25, wherein F is 6-fluoro-pyrid-2-yl;     -   1.42 Any of formulae 1.4-1.25, wherein F is pyrimidinyl (for         example, pyrimidin-2-yl);     -   1.43 Any of formulae 1.4-1.25, wherein F is triazolyl (e.g.,         1,2,4-triazol-1-yl);     -   1.44 Any of formulae 1.4-1.25, wherein F is diazolyl (e.g.,         pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for         example, imidazol-1-yl, 4-methylimidazolyl,         1-methylimidazol-2-yl);     -   1.45 Any of formulae 1.4-1.25, wherein F is         C₁₋₆alkyl-oxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazolyl);     -   1.46 Any of formulae 1.4-1.25, wherein F is amino (e.g., —NH₂);     -   1.47 Any of formulae 1.4-1.25, wherein F is C₁₋₆alkoxy;     -   1.48 Any of formulae 1.4-1.25, wherein F is O-haloC₁₋₆alkyl         (e.g., —O—CF₃);     -   1.49 Any of formulae 1.1-1.25, wherein F is —C(O)—R₁₃;     -   1.50 Any of formulae 1.1-1.25, wherein F is —N(R₁₄)(R₁₅);     -   1.51 Any of formulae 1.1-1.25, wherein F is C₁₋₆alkylsulfonyl;     -   1.52 Any of formulae 1.1-1.25, wherein F is methylsulfonyl or         —S(O)₂CH₃;     -   1.53 Formula I or any of 1.1-1.24, wherein R₃ is a substituted         heteroarylaklyl, e.g., substituted with haloalkyl;     -   1.54 Formula I or any of 1.1-1.24, wherein R₃ is attached to one         of the nitrogens on the pyrazolo portion of Formula I and is a         moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F);         -   and R₁₀ is halogen, alkyl, cycloalkyl, haloalkyl (e.g.,             trifluoromethyl), aryl (e.g., phenyl), heteroaryl (e.g.,             pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl             (for example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl             (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g.,             tetrazol-5-yl), alkoxadiazolyl (e.g.,             5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl),             alkyl sulfonyl (e.g., methyl sulfonyl), arylcarbonyl (e.g.,             benzoyl), or heteroarylcarbonyl, alkoxycarbonyl, (e.g.,             methoxycarbonyl), aminocarbonyl; preferably phenyl or             pyridyl, e.g., 2-pyridyl; provided that when X, Y or X is             nitrogen, R₈, R₉ or R₁₀, respectively, is not present;

    -   1.55 Formula 1.54, wherein R₃ is a moiety of Formula A, R₈, R₉,         R₁₁ and R₁₂ are each H and R₁₀ is phenyl;

    -   1.56 Formula 1.54, wherein R₃ is a moiety of Formula A, R₈, R₉,         R₁₁ and R₁₂ are each H and R₁₀ is pyridyl or thiadiazolyl;

    -   1.57 Formula 1.54, wherein R₃ is a moiety of Formula A, R₈, R₉,         R₁₁ and R₁₂ are each H and R₁₀ is pyrid-2-yl optionally         substituted with halo (e.g., fluoro);

    -   1.58 Formula 1.54, wherein R₃ is a moiety of Formula A and X, Y         and Z are all C,

    -   1.59 Formula 1.54, wherein R₁₀ is pyrimidinyl;

    -   1.60 Formula 1.54, wherein R₁₀ is 5-fluoropyrmidinyl;

    -   1.61 Formula 1.54, wherein R₁₀ is pyrazol-1-yl;

    -   1.62 Formula 1.54, wherein R₁₀ is 1,2,4-triazol-1-yl;

    -   1.63 Formula 1.54, wherein R₁₀ is aminocarbonyl;

    -   1.64 Formula 1.54, wherein R₁₀ is methylsulfonyl;

    -   1.65 Formula 1.54, wherein R₁₀ is 5-methyl-1,2,4-oxadiazol-3-yl;

    -   1.66 Formula 1.54, wherein R₁₀ is 5-thioxopyrimidin-2-yl;

    -   1.67 Formula 1.54, wherein R₁₀ is trifluoromethyl;

    -   1.68 Formula 1.54, wherein R₃ is a moiety of Formula A, X and Z         are C, and Y is N;

    -   1.69 Formula I or any of 1.1-1.68, wherein R₂ is H; C₁₋₆alkyl         (e.g., isopropyl, isobutyl, neopentyl, 2-methylbutyl,         2,2-dimethylpropyl) wherein said alkyl group is optionally         substituted with halo (e.g., fluoro) or hydroxy (e.g.,         1-hydroxypropan-2-yl, 3-hydroxy-2-methylpropyl);         —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., cyclopentyl, cyclohexyl)         optionally substituted with one or more amino (e.g., —NH₂), for         example, 2-aminocyclopentyl or 2-aminocyclohexyl), wherein said         cycloalkyl optionally contains one or more heteroatom selected         from N and O and is optionally substituted with C₁₋₆alkyl (e.g.,         1-methyl-pyrrolindin-2-yl, 1-methyl-pyrrolindin-3-yl,         1-methyl-pyrrolindin-2-yl-methyl or         1-methyl-pyrrolindin-3-yl-methyl); C₃₋₈heterocycloalkyl (e.g.,         pyrrolidinyl, for example, pyrrolidin-3-yl) optionally         substituted with C₁₋₆alkyl (e.g., methyl), for example,         1-methylpyrrolidin-3-yl; C₃₋₈cycloalkyl-C₁₋₆alkyl (e.g.,         cyclopropylmethyl); haloC₁₋₆alkyl (e.g., trifluoromethyl,         2,2,2-trifluoroethyl); —N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g.,         2-(dimethylamino)ethyl,2-aminopropyl); hydroxyC₁₋₆alkyl (e.g.,         (e.g., 3-hydroxy-2-methylpropyl, 1-hydroxyprop-2-yl);         arylC₀₋₆alkyl (e.g., benzyl); heteroarylC₁₋₆alkyl (e.g.,         pyridinylmethyl); C₁₋₆alkoxyarylC₁₋₆alkyl (e.g.,         4-methoxybenzyl); -G-J wherein: G is a single bond or, alkylene         (e.g., methylene) and J is cycloalkyl or heterocycloalkyl (e.g.,         oxetan-2-yl, pyrolyin-3-yl, pyrolyin-2-yl) optionally         substituted with C₁₋₆alkyl (e.g., (1-methylpyrrolidin-2-yl));

    -   1.70 Formula 1.69, wherein R₂ is H,

    -   1.71 Formula 1.69, wherein R₂ is C₁₋₆alkyl (e.g., isopropyl,         isobutyl, neopentyl, 2-methylbutyl, 2,2-dimethylpropyl) wherein         said alkyl group is optionally substituted with halo (e.g.,         trifluoroethyl) or hydroxy (e.g., 1-hydroxypropan-2-yl,         3-hydroxy-2-methylpropyl);

    -   1.72 Formula 1.69, wherein R₂ is isobutyl;

    -   1.73 Formula 1.69, wherein R₂ is 3-hydroxy-2-methylpropyl;

    -   1.74 Formula 1.69, wherein R₂ is 1-hydroxypropan-2-yl;

    -   1.75 Formula 1.69, wherein R₂ is C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g.,         cyclopentyl, cyclohexyl) optionally substituted with one or more         amino (e.g., —NH₂), for example, 2-aminocyclopentyl or         2-aminocyclohexyl), wherein said cycloalkyl optionally contains         one or more heteroatom selected from N and O and is optionally         substituted with C₁₋₆alkyl (e.g., 1-methyl-pyrrolindin-2-yl,         1-methyl-pyrrolindin-3-yl, 1-methyl-pyrrolindin-2-yl-methyl or         1-methyl-pyrrolindin-3-yl-methyl);

    -   1.76 Formula 1.69, wherein R₂ is 1-methyl-pyrrolindin-2-yl,         1-methyl-pyrrolindin-3-yl, 1-methyl-pyrrolindin-2-yl-methyl or         1-methyl-pyrrolindin-3-yl-methyl;

    -   1.77 Formula 1.69, wherein R₂ is C₃₋₈heterocycloalkyl (e.g.,         pyrrolidinyl, for example, pyrrolidin-3-yl) optionally         substituted with C₁₋₆alkyl (e.g., methyl), for example,         1-methylpyrrolidin-3-yl;

    -   1.78 Formula 1.69, wherein R₂ is 1-methylpyrrolidin-3-yl;

    -   1.79 Formula 1.69, wherein R₂ is C₃₋₈cycloalkyl-C₁₋₆alkyl (e.g.,         cyclopropylmethyl);

    -   1.80 Formula 1.69, wherein R₂ is —N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g.,         2-(dimethylamino)ethyl, 2-aminopropyl);

    -   1.81 Formula 1.69, wherein R₂ is heteroarylC₁₋₆alkyl (e.g.,         pyridinylmethyl),

    -   1.82 Formula 1.69, wherein R₂ is C₁₋₆alkoxyarylC₁₋₆alkyl (e.g.,         4-methoxybenzyl;

    -   1.83 Formula 1.69, wherein R₂ is arylC₀₋₆alkyl (e.g., benzyl);

    -   1.84 Formula 1.69, wherein R₂ is cyclopentyl or cyclohexyl;

    -   1.85 Formula I or any of 1.1-1.68, wherein R₂ is -G-J; G is a         single bond or, alkylene (e.g., methylene); and J is cycloalkyl         or heterocycloalkyl (e.g., oxetan-2-yl, pyrolyin-3-yl,         pyrolyin-2-yl) optionally substituted with C₁₋₆alkyl (e.g.,         (1-methylpyrrolidin-2-yl));

    -   1.86 Formula 1.85, wherein G is alkylene (e.g., methylene);

    -   1.87 Formula 1.85, wherein G is methylene;

    -   1.88 Formula 1.85, wherein J is cycloalkyl or heterocycloalkyl         (e.g., oxetan-2-yl, pyrolyin-3-yl, pyrolyin-2-yl) optionally         substituted with alkyl (e.g., 1-methylpyrrolidin-2-yl);

    -   1.89 Formula 1.85, wherein J is oxetan-2-yl, pyrolyin-3-yl,         pyrolyin-2-yl;

    -   1.90 Formula 1.85, wherein J is (1-methylpyrrolidin-2-yl);

    -   1.91 Any of the preceding formulae wherein R₄ and R₅ are         independently H, C₁₋₆alkyl (e.g., methyl, isopropyl),         C₃₋₈cycloalkyl (e.g., cyclopentyl), C₃₋₈heterocycloalkyl (e.g.,         pyrrolidin-3-yl), or aryl (e.g., phenyl) or heteroaryl (e.g.,         pyrid-4-yl, pyrid-2-yl or pyrazol-3-yl) wherein said aryl or         heteroaryl is optionally substituted with halo (e.g.,         4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkoxy         C₁₋₆alkyl, or C₁₋₆alkoxy or another aryl group (e.g.,         biphenyl-4-ylmethyl);

    -   1.92 Formula 1.91, wherein either R₄ or R₅ is H,

    -   1.93 Formula 1.91, wherein either R₄ or R₅ is C₁₋₆alkyl (e.g.,         methyl, isopropyl);

    -   1.94 Formula 1.91, wherein either R₄ or R₅ is isopropyl;

    -   1.95 Formula 1.91, wherein either R₄ or R₅ is C₃₋₈cycloalkyl         (e.g., cyclopentyl);

    -   1.96 Formula 1.91, wherein either R₄ or R₅ is         C₃₋₈heterocycloalkyl (e.g., pyrrolidin-3-yl);

    -   1.97 Formula 1.91, wherein either R₄ or R₅ is aryl (e.g.,         phenyl) optionally substituted with halo (e.g., 4-fluorophenyl),         hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or         another aryl group (e.g., biphenyl-4-ylmethyl);

    -   1.98 Formula 1.91, wherein either R₄ or R₅ is 4-hydroxyphenyl;

    -   1.99 Formula 1.91, wherein either R₄ or R₅ is 4-fluorophenyl;

    -   1.100 Formula 1.91, wherein either R₄ or R₅ is heteroaryl (e.g.,         pyrid-4-yl, pyrid-2-yl or pyrazol-3-yl) optionally substituted         with halo (e.g., 4-fluorophenyl), hydroxy (e.g.,         4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group         (e.g., biphenyl-4-ylmethyl);

    -   1.101 Formula 1.91, wherein either R₄ or R₅ is phenyl;

    -   1.102 Any of the foregoing formulae, wherein R₆ is H, C₁₋₆alkyl         (e.g., methyl) or C₃₋₈cycloalkyl;

    -   1.103 Formula 1.102, wherein R₆ is H;

    -   1.104 Formula 1.102, wherein R₆ is C₁₋₆alkyl (e.g., methyl);

    -   1.105 Formula 1.102, wherein R₆ is methyl;

    -   1.106 Any of the foregoing formulae, wherein R¹³ is         —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g., methyl), —OC₁₋₆alkyl (e.g.,         —OCH₃), haloC₁₋₆alkyl, aryl (for example phenyl), or heteroaryl;

    -   1.107 Formula 1.106, wherein R¹³ is —N(R₁₄)(R₁₅);

    -   1.108 Formula 1.106, wherein R¹³ is C₁₋₆alkyl (e.g., methyl);

    -   1.109 Formula 1.106, wherein R¹³ is —OC₁₋₆alkyl (e.g., —OCH₃),

    -   1.110 Formula 1.106, wherein R¹³ is —OCH₃;

    -   1.111 Formula 1.106, wherein R¹³ is haloC₁₋₆alkyl (e.g.,         trifluoromethyl);

    -   1.112 Formula 1.106, wherein R¹³ is trifluoromethyl;

    -   1.113 Formula 1.106, wherein R¹³ is aryl (e.g., phenyl);

    -   1.114 Formula 1.106, wherein R¹³ is heteroaryl (e.g.,         pyridinyl);

    -   1.115 Any of the preceding formulae, wherein R₁₄ and R₁₅ are         independently H or C₁₋₆alkyl (e.g., methyl);

    -   1.116 Formula I or any of 1.1-1.115, wherein either R₁₄ or R₁₅         is independently H;

    -   1.117 Formula I or any of 1.1-1.115, wherein either R₁₄ or R₁₅         is C₁₋₆alkyl (e.g., methyl);

    -   1.118 Formula I or any of 1.1-1.115, wherein either R₁₄ or R₁₅         is methyl;

    -   1.119 any of the preceding formulae wherein the compound of         formula I is

-   -   1.120 any of the preceding formulae wherein compound of formula         I is

-   -   1.121 any of the preceding formulae wherein compound of formula         I is selected from a group consisting of:

-   -   1.122 any of the preceding formulae wherein the compounds         inhibit phosphodiesterase-mediated (e.g., PDE1-mediated,         especially PDE1B-mediated) hydrolysis of cGMP, e.g., with an         IC₅₀ of less than 1 μM, preferably less than 500 nM, preferably         less than 200 nM in an immobilized-metal affinity particle         reagent PDE assay, for example, as described in Example 5,

in free, salt or prodrug form.

In a particular embodiment, the compound of the present invention is the compound of the present invention is a 3-amino-4-(thioxo)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, e.g., a compound of Formula I or II, wherein Q is C(═S) and the rest of the substituents are as defined in any of the formulae above. In another preferred embodiment, 7-Isobutyl-5-methyl-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-4-thioxo-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one or 7-Isobutyl-5-methyl-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-4-(imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one, in free, or salt form. In still another embodiment, the compound of the invention is 2-(4-(1H-1,2,4-triazol-1-yl)benzyl)-5-methyl-7-neopentyl-3-(phenylamino)-4-thioxo-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one.

In still another particular embodiment, the Compound of the Invention is a Compound of Formula I wherein

-   -   (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—;     -   (ii) R₁ is H or alkyl (e.g., methyl);     -   (iii) R₂ is H, alkyl (e.g., isobutyl, 2-methylbutyl,         2,2-dimethyl propyl), cycloalkyl (e.g., cyclopentyl,         cyclohexyl), haloalkyl (e.g., trifluoromethyl,         2,2,2-trifluoroethyl), alkylaminoalkyl (e.g.,         2-(dimethylamino)ethyl), hydroxyalkyl (e.g., 3-hydroxy-2-methyl         propyl), arylalkyl (e.g., benzyl), heteroarylalkyl (e.g.,         pyridylmethyl), or alkoxyarylalkyl (e.g., 4-methoxybenzyl);     -   (iv) R₃ is a substituted heteroarylaklyl, e.g., substituted with         haloalkyl or     -   R₃ is attached to one of the nitrogens on the pyrazolo portion         of Formula 1 and is     -   a moiety of Formula A

wherein X, Y and Z are, independently, N or C, and R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F); and R₁₀ is halogen, alkyl, cycloalkyl, haloalkyl (e.g., trifluoromethyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl), alkoxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl), alkyl sulfonyl (e.g., methyl sulfonyl), arylcarbonyl (e.g., benzoyl), or heteroarylcarbonyl, alkoxycarbonyl, (e.g., methoxycarbonyl), aminocarbonyl; preferably phenyl or pyridyl, e.g., 2-pyridyl; provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀, respectively, is not present;

-   -   (v) R₄ is aryl (e.g., phenyl) or heteroaryl;     -   (vi) R₅ is H, alkyl, cycloalkyl (e.g., cyclopentyl), heteroaryl,         aryl, p-benzylaryl (e.g., biphenyl-4-ylmethyl);     -   (vii) R₆ is H, C₁₋₆alkyl (e.g., methyl) or C₃₋₈cycloalkyl;     -   (viii) R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g., methyl),         —OC₁₋₆alkyl (e.g., —OCH₃), haloC₁₋₆alkyl(trifluoromethyl), aryl         (e.g., phenyl), or heteroaryl; and     -   (ix) R₁₄ and R is are independently H or C₁₋₆alkyl,         in free, salt or prodrug form (hereinafter, Compound of Formula         I(i)).

In still another embodiment, the Compound of the Invention is a Compound of Formula I wherein

-   -   (i) R₁ is H or alkyl (e.g., methyl);     -   (ii) R₂ is H, alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl,         2,2-dimethyl propyl), cycloalkyl (e.g., cyclopentyl,         cyclohexyl), haloalkyl (e.g., trifluoromethyl,         2,2,2-trifluoroethyl), alkylaminoalkyl (e.g.,         2-(dimethylamino)ethyl), hydroxyalkyl (e.g., 3-hydroxy-2-methyl         propyl), arylalkyl (e.g., benzyl), heteroarylalkyl (e.g.,         pyridylmethyl), or alkoxyarylalkyl (e.g., 4-methoxybenzyl);     -   (iii) R₃ is D-E-F wherein         -   1. D is single bond, alkylene (e.g., methylene), or             arylalkylene (e.g., benzylene or —CH₂C₆H₄—);     -   2. E is a alkylene (e.g., methylene, ethynylene,         prop-2-yn-1-ylene), arylene (e.g., phenylene or —C₆H₄—),         alkylarylene (e.g., -benzylene- or —CH₂C₆H₄—), aminoalkylene         (e.g., —CH₂—N(H)—) or amino (e.g., —N(H)—); and         -   3. F is alkyl (e.g., isobutyl), aryl (e.g., phenyl),             heteroaryl (e.g., pyrid-2-yl, 1,2,4-triazolyl),             heteroC₃₋₈cycloalkyl (e.g., pyrrolidin-1-yl), amino (e.g.,             —NH₂), C₁₋₆alkoxy, or O-haloalkyl (e.g., O—CF₃);     -   (iv) R₄ is aryl (e.g., phenyl), heteroaryl (e.g., pyrid-4-yl,         pyrid-2-yl or pyrazol-3-yl) or heterocycloalkyl (e.g.,         pyrrolidin-3-yl); and     -   (v) R₅ is H, alkyl, cycloalkyl (e.g., cyclopentyl), heteroaryl,         aryl, p-benzylaryl (e.g., biphenyl-4-ylmethyl);     -   (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl) or C₃₋₈cycloalkyl;     -   (vii) R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g., methyl), —OC₁₋₆alkyl         (e.g., —OCH₃), haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g.,         phenyl), or heteroaryl; and     -   (viii) R₁₄ and R₁₅ are independently H or alkyl,         wherein “alk”, “alkyl”, “haloalkyl” or “alkoxy” refers to C₁₋₆         alkyl and “cycloalkyl” refers to C₃₋₈ cycloalkyl unless         specifically specified;         in free, salt or prodrug form (hereinafter, Compound of Formula         I(ii)).

If not otherwise specified or clear from context, the following terms herein have the following meanings:

-   -   (a) “Alkyl” as used herein is a saturated or unsaturated         hydrocarbon moiety, preferably saturated, preferably having one         to six carbon atoms, which may be linear or branched, and may be         optionally mono-, di- or tri-substituted, e.g., with halogen         (e.g., chloro or fluoro), hydroxy, or carboxy.     -   (b) “Cycloalkyl” as used herein is a saturated or unsaturated         nonaromatic hydrocarbon moiety, preferably saturated, preferably         comprising three to eight carbon atoms, at least some of which         form a nonaromatic mono- or bicyclic, or bridged cyclic         structure, and which may be optionally substituted, e.g., with         halogen (e.g., chloro or fluoro), hydroxy, or carboxy. Wherein         the cycloalkyl optionally contains one or more atoms selected         from N and O and/or S, said cycloalkyl may optionally be a         heterocycloalkyl.     -   (c) “Heterocycloalkyl” is, unless otherwise indicated, saturated         or unsaturated nonaromatic hydrocarbon moiety, preferably         saturated, preferably comprising three to nine carbon atoms, at         least some of which form a nonaromatic mono- or bicyclic, or         bridged cyclic structure, wherein at least one carbon atom is         replaced with N, O or S, which heterocycloalkyl may be         optionally substituted, e.g., with halogen (e.g., chloro or         fluoro), hydroxy, or carboxy.     -   (d) “Aryl” as used herein is a mono or bicyclic aromatic         hydrocarbon, preferably phenyl, optionally substituted, e.g.,         with alkyl (e.g., methyl), halogen (e.g., chloro or fluoro),         haloalkyl (e.g., trifluoromethyl), hydroxy, carboxy, or an         additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl).     -   (e) “Heteroaryl” as used herein is an aromatic moiety wherein         one or more of the atoms making up the aromatic ring is sulfur         or nitrogen rather than carbon, e.g., pyridyl or thiadiazolyl,         which may be optionally substituted, e.g., with alkyl, halogen,         haloalkyl, hydroxy or carboxy.     -   (f) Wherein E is phenylene, the numbering is as follows:

-   -   (g) It is intended that wherein the substituents end in “ene”,         for example, alkylene, phenylene or arylalkylene, said         substitutents are intended to bridge or be connected to two         other substituents. Therefore, methylene is intended to be —CH₂—         and phenylene intended to be —C₆H₄— and arylalkylene is intended         to be —C₆H₄—CH₂— or —CH₂—C₆H₄—.

Compounds of the Invention may exist in free or salt form, e.g., as acid addition salts. In this specification unless otherwise indicated, language such as “Compounds of the Invention” is to be understood as embracing the compounds described herein, e.g., 3-amino-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6(7H)-ones and their 4-imino and 4-thioxo derivatives, e.g., optionally substituted 3-amino-4-(thioxo or imino)-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6(7H)-ones or 3-amino-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, a Compound of Formula I, or any of 1.11.122, a Compound of Formula I(i) or I(ii), a Compound of Formula II, e.g., any of 2.1-2.64, or any of Compound of Formula II(a)-II(e), in any form, for example free or acid addition salt form, or where the compounds contain acidic substituents, in base addition salt form. The Compounds of the Invention are intended for use as pharmaceuticals, therefore pharmaceutically acceptable salts are preferred. Salts which are unsuitable for pharmaceutical uses may be useful, for example, for the isolation or purification of free Compounds of the Invention or their pharmaceutically acceptable salts, are therefore also included.

Compounds of the Invention may in some cases also exist in prodrug form. A prodrug form is compound which converts in the body to a Compound of the Invention. For example, when the Compounds of the Invention contain hydroxy (or carboxy) substituents, these substituents may form physiologically hydrolysable and acceptable esters, e.g., C₁₋₄alkyl carboxylic acid ester. As used herein, “physiologically hydrolysable and acceptable ester” means esters of Compounds of the Invention which are hydrolysable under physiological conditions to yield acids (in the case of Compounds of the Invention which have hydroxy substituents) or alcohols (in the case of Compounds of the Invention which have carboxy substituents) which are themselves physiologically tolerable at doses to be administered. Therefore, wherein the Compound of the Invention contains a hydroxy group, for example, Compound-OH, the acyl ester prodrug of such compound, i.e., Compound-O—C(O)—C₁₋₄alkyl, can hydrolyze in the body to form physiologically hydrolysable alcohol (Compound-OH) on the one hand and acid on the other (e.g., HOC(O)—C₁₋₄alkyl). Alternatively, wherein the Compound of the Invention contains a carboxylic acid, for example, Compound-C(O)OH, the acid ester prodrug of such compound, Compound-C(O)O—C₁₋₄alkyl can hydrolyze to form Compound-C(O)OH and HO—C₁₋₄alkyl. As will be appreciated, the term thus embraces conventional pharmaceutical prodrug forms.

The invention also provides methods of making the Compounds of the Invention and methods of using the Compounds of the Invention for treatment of diseases and disorders as set forth below (especially treatment of diseases characterized by reduced dopamine D1 receptor signaling activity, such as Parkinson's disease, Tourette's Syndrome, Autism, fragile X syndrome, ADHD, restless leg syndrome, depression, cognitive impairment of schizophrenia, narcolepsy and diseases that may be alleviated by the enhancement of progesterone-signaling such as female sexual dysfunction), or a disease or disorder such as psychosis or glaucoma). This list is not intended to be exhaustive and may include other diseases and disorders as set forth below.

In another embodiment, the invention further provides a pharmaceutical composition comprising a Compound of the Invention, e.g., 3-amino-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6(7H)-ones and their 4-imino and 4-thioxo derivatives, e.g., optionally substituted 3-amino-4-(thioxo or imino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, optionally substituted 3-amino-4-(thioxo or imino)-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, 3-amino-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6(7H)-ones, a Compound of Formula I, or any of 1.11.122, a Compound of Formula I(i) or I(ii), a Compound of Formula II, e.g., any of 2.1-2.64, or any of the Compound of Formula II(a)-II(e), in free, pharmaceutically acceptable salt or prodrug form, in admixture with a pharmaceutically acceptable carrier.

DETAILED DESCRIPTION OF THE INVENTION Methods of Making Compounds of the Invention

The Compounds of the Invention and their pharmaceutically acceptable salts may be made using the methods as described and exemplified herein and by methods similar thereto and by methods known in the chemical art. Such methods include, but not limited to, those described below. In the description of the synthetic methods described herein, it is to be understood that all proposed reaction conditions, including choice of solvent, reaction atmosphere, reaction temperature, duration of the experiment and workup procedures, are chosen to be the conditions standard for that reaction, which should be readily recognized by one skilled in the art. Therefore, at times, the reaction may require to be run at elevated temperature or for a longer or shorter period of time. It is understood by one skilled in the art of organic synthesis that functionality present on various portions of the molecule must be compatible with the reagents and reactions proposed. If not commercially available, starting materials for these processes may be made by procedures, which are selected from the chemical art using techniques which are similar or analogous to the synthesis of known compounds. In particular, the intermediates and starting materials for the Compounds of the Invention may be prepared by methods and processes as described in PCT/US2007/070551. All references cited herein are hereby incorporated by reference in their entirety.

The Compounds of the Invention include their enantiomers, diastereoisomers, tautomers and racemates, as well as their polymorphs, hydrates, solvates and complexes. Some individual compounds within the scope of this invention may contain double bonds. Representations of double bonds in this invention are meant to include both the E and the Z isomer of the double bond. In addition, some compounds within the scope of this invention may contain one or more asymmetric centers. This invention includes the use of any of the optically pure stereoisomers as well as any combination of stereoisomers.

It is also intended that the Compounds of the Invention encompass their stable and unstable isotopes. Stable isotopes are nonradioactive isotopes which contain one additional neutron compared to the abundant nuclides of the same species (i.e., element). It is expected that the activity of compounds comprising such isotopes would be retained, and such compound would also have utility for measuring pharmacokinetics of the non-isotopic analogs. For example, the hydrogen atom at a certain position on the Compounds of the Invention may be replaced with deuterium (a stable isotope which is non-raradioactive). Examples of known stable isotopes include, but not limited to, deuterium, ¹³C, ¹⁵N, ¹⁸O. Alternatively, unstable isotopes, which are radioactive isotopes which contain additional neutrons compared to the abundant nuclides of the same species (i.e., element), e.g., ¹²³I, ¹³¹I, ¹²⁵I, ¹¹C, ¹⁸F, may replace the corresponding abundant species of I, C and F. Another example of useful isotope of the compound of the invention is the ¹¹C isotope. These radio isotopes are useful for radio-imaging and/or pharmacokinetic studies of the compounds of the invention.

Melting points are uncorrected and (dec) indicates decomposition. Temperature are given in degrees Celsius (° C.); unless otherwise stated, operations are carried out at room or ambient temperature, that is, at a temperature in the range of 18-25° C. Chromatography means flash chromatography on silica gel; thin layer chromatography (TLC) is carried out on silica gel plates. NMR data is in the delta values of major diagnostic protons, given in parts per million (ppm) relative to tetramethylsilane (TMS) as an internal standard. Conventional abbreviations for signal shape are used. Coupling constants (J) are given in Hz. For mass spectra (MS), the lowest mass major ion is reported for molecules where isotope splitting results in multiple mass spectral peaks Solvent mixture compositions are given as volume percentages or volume ratios. In cases where the NMR spectra are complex, only diagnostic signals are reported.

TERMS AND ABBREVIATIONS

BuLi=n-butyllithium

Bu^(t)OH=tert-butyl alcohol,

CAN=ammonium cerium (IV) nitrate,

DIPEA=diisopropylethylamine,

DMF=N,N-dimethylforamide,

DMSO=dimethyl sulfoxide,

Et₂O=diethyl ether,

EtOAc=ethyl acetate,

equiv.=equivalent(s),

h=hour(s),

HPLC=high performance liquid chromatography,

LDA=lithium diisopropylamide

MeOH=methanol,

NBS=N-bromosuccinimide

NCS=N-chlorosuccinimide

NaHCO₃=sodium bicarbonate,

NH₄OH=ammonium hydroxide,

Pd₂(dba)₃=tris[dibenzylideneacetone]dipalladium(0)

PMB=p-methoxybenzyl,

POCl₃=phosphorous oxychloride,

SOCl₂=thionyl chloride,

TFA=trifluoroacetic acid,

THF=tetrahedrofuran.

The synthetic methods in this invention are illustrated below. The significances for the R groups are as set forth in any of the formulae above, e.g., for formula I, I(i), I(ii), II, II(a)-II(e) unless otherwise indicated.

In an aspect of the invention, intermediate compounds of formula IIb can be synthesized by reacting a compound of formula IIa with a dicarboxylic acid, acetic anhydride and acetic acid mixing with heat for about 3 hours and then cooled:

wherein R₁ is H or C₁₋₄alkyl [e.g., methyl].

Intermediate IIc can be prepared by for example reacting a compound of IIb with for example a chlorinating compound such as POCl₃, sometimes with small amounts of water and heated for about 4 hours and then cooled:

Intermediate IId may be formed by reacting a compound of IIc with for example a P¹-L in a solvent such as DMF and a base such as K₂CO₃ at room temperature or with heating:

wherein P¹ is a protective group [e.g., p-methoxybenzyl group (PMB)]; L is a leaving group such as a halogen, mesylate, or tosylate.

Intermediate IIe may be prepared by reacting a compound of IId with hydrazine or hydrazine hydrate in a solvent such as methanol and refluxed for about 4 hours and then cooled:

Intermediate IIf can be synthesized by reacting a compound of IIe with for example an aryl isothiocyanate or isocyanate in a solvent such as DMF and heated at 110° C. for about 2 days and then cooled:

-   -   wherein R₄ is, e.g., (hetero)aryl or (hetero)arylmethyl [e.g.,         phenyl or benzyl].

Intermediate IIg may be formed by reacting a compound of IIf with for example a R₃-L in a solvent such as DMF and a base such as K₂CO₃ at room temperature or with heating:

-   -   wherein R₃ is as defined previously in Formula I or II [e.g.         -D-E-F or moiety of Formula A]; L is a leaving group such as a         halogen, mesylate, or tosylate.

Intermediate IIh may be synthesized from a compound of IIg by removing the protective group P¹ with an appropriate method. For example, if P¹ is a p-methoxybenzyl group, then it can be removed with AlCl₃ in the presence of anisole at room temperature:

Intermediate I may be formed by reacting a compound of IIh with for example a R₂-L and/or R₅-L in a solvent such as DMF and a base such as K₂CO₃ at room temperature or with heating:

-   -   wherein R₂ and R₅ are as defined previously [e.g. R₂ is a         cyclopentyl group and R₅ is phenyl]; L is a leaving group such         as a halogen, mesylate, or tosylate.

There is an alternative approach for the synthesis of Intermediate I.

Intermediate IIIa may be formed by reacting a compound of IIc with for example a R₂-L in a solvent such as DMF and a base such as K₂CO₃ at room temperature or with heating:

wherein R₂ is as defined in any of the formulae disclosed herein and L is a leaving group such as halogen, mesylate, or tosylate

Intermediate IIIb may be prepared by reacting a compound of IIIa with hydrazine or hydrazine hydrate in a solvent such as methanol and heated for about several hours and then cooled:

Intermediate IIIc can be synthesized by reacting a compound of IIIb with for example an aryl isothiocyanate or isocyanate in a solvent such as DMF and heated at 110° C. for about 2 days and then cooled:

Compound I may be formed by reacting a compound of IIIc with for example a R₃-L in a solvent such as DMF ands a base such as K₂CO₃ at room temperature or with heating. The obtained product (IIId) may further react with for example a R₅-L under basic condition to give compound I wherein R₅ and R₃ are as previously defined in any of the formulae disclosed herewith, and L is a leaving group such as halogen, mesylate or tosylate:

The compound of Formula (I)-A shown below can be synthesized using similar synthetic methods described above. In general, N-1 substituted compound is obtained as a minor product of N-alkylation reaction, as shown here.

The third approach for making compound I is described below.

Intermediate IVa may be formed by for example reacting a compound of IIIb with POCl₃ and DMF.

Intermediate IVb may be formed by reacting a compound of IVa with for example a R₃-L in a solvent such as DMF and a base such as K₂CO₃ at room temperature or with heating.

wherein R₃ is as previously defined in any of the formulae disclosed herewith, and L is a leaving group such as halogen, mesylate or tosylate.

Intermediate IVc may be formed by reacting a compound of IVb with for example NCS, NBS or I₂ in a solvent such as THF and a base such as LDA or BuLi at low temperature.

Compound I may be formed by the amination of IVc, IVd, or IIIc, e.g., with R₄NH₂ or R₅NH₂ under basic conditions. An appropriate catalyst such as Pd₂(dba)₃ may be required in order to get good yields, particularly when R₄NH₂ or R₅NH₂ is an aryl amine or hetereoaryl amine

The 4-thioxo Compounds of the Invention, e.g., Compounds of Formula I or II wherein Q is C(═S) may then be prepared by reacting Intermediate I or any of the with P₄S₁₀ in a microwave vial in the presence of a base, e.g., pyridine, and heating the mixture to an elevated temperature, e.g., in a microwave, e.g., to about 150° C. The 4-imino Compounds of the Invention, e.g., Compounds of Formula I or II, wherein Q is C(═N(R₆)) may in turn be converted from the thioxo derivative (i.e., Compounds of Formula I or II, wherein with Q is X(═S)) by reacting the 4-thioxo derivative with NH₂(R₆) in the presence of HgCl₂, e.g., in a solvent such as THF, and heating the reaction mixture to an elevated temperature, e.g., in a microwave, e.g., to about 110° C.

The Compounds of the Invention, e.g., Compounds of Formula I or II wherein Q is C(R₁₄)(R₁₅) may also be prepared by reacting Intermediate I with a reducing agent, e.g., diisobutylaluminum hydride (DIBAL-H), lithium aluminum hydride, sodium borohydride, preferably, DIBAL-H.

The invention thus provides methods of making a 4-thioxo Compounds of the Invention, e.g., Compound of Formula I or II, wherein Q of is C(═S) as hereinbefore described, for example, comprising reacting a 7-R₂-5-R₃-3-(N(R4)(R5))-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione of Formula I with P₄S₁₀ in the presence of a base, e.g., pyridine, and heating the reaction mixture to an elevated temperature, e.g., to >50° C., e.g., >100° C., e.g., >150° C., for example, in a microwave to about 150° C.

The invention also provides methods of making 4-imino Compounds of the Invention, e.g., Compounds of Formula I or II, wherein Q of Formula I is C(═N(R₆)) as hereinbefore described, for example, comprising reacting a the Compound of Formula I or II, wherein Q is C(═S), with NH₂(R₆) in the presence of HgCl₂, e.g., in a solvent such as THF, and heating the reaction mixture in a microwave, e.g., to >50° C., e.g., >75° C., e.g., >100° C., for example, in a microwave to about 110° C.

The invention also provides methods of making pyrazolo[3,4-d]pyrimidin-6-one Compounds of the Invention, e.g., Compounds of Formula I or II, wherein Q is CH₂ comprising reacting Intermediate I with a reducing agent, e.g., diisobutylaluminum hydride (DIBAL-H), lithium aluminum hydride, sodium borohydride, preferably, DIBAL-H.

Alternatively, the Compounds of the Invention, e.g., Compounds of Formula I or II wherein Q is C(═S), C(═N(R₆)) or CH₂, may be prepared first before attaching on R₁, R₂, R₃ and/or R₅. Therefore, the Compounds of the Invention may be prepared as follows:

Compound of Formula (I) may be formed by the amination of IVc-A, IVd-A, or IIIc-A under basic conditions. An appropriate catalyst such as Pd₂(dba)₃ may be required in order to get good yields.

Methods of Using Compounds of the Invention

The Compounds of the Invention are useful in the treatment of diseases characterized by disruption of or damage to cAMP and cGMP mediated pathways, e.g., as a result of increased expression of PDE1 or decreased expression of cAMP and cGMP due to inhibition or reduced levels of inducers of cyclic nucleotide synthesis, such as dopamine and nitric oxide (NO). By preventing the degradation of cAMP and cGMP by PDE1B, thereby increasing intracellular levels of cAMP and cGMP, the Compounds of the Invention potentiate the activity of cyclic nucleotide synthesis inducers.

The invention provides methods of treatment of any one or more of the following conditions:

-   -   (i) Neurodegenerative diseases, including Parkinson's disease,         restless leg, tremors, dyskinesias, Huntington's disease,         Alzheimer's disease, and drug-induced movement disorders;     -   (ii) Mental disorders, including depression, attention deficit         disorder, attention deficit hyperactivity disorder, bipolar         illness, anxiety, sleep disorders, e.g., narcolepsy, cognitive         impairment, dementia, Tourette's syndrome, autism, fragile X         syndrome, psychostimulant withdrawal, and drug addiction;     -   (iii) Circulatory and cardiovascular disorders, including         cerebrovascular disease, stroke, congestive heart disease,         hypertension, pulmonary hypertension, and sexual dysfunction;     -   (iv) Respiratory and inflammatory disorders, including asthma,         chronic obstructive pulmonary disease, and allergic rhinitis, as         well as autoimmune and inflammatory diseases;     -   (v) Any disease or condition characterized by low levels of cAMP         and/or cGMP (or inhibition of cAMP and/or cGMP signaling         pathways) in cells expressing PDE1; and/or     -   (vi) Any disease or condition characterized by reduced dopamine         D1 receptor signaling activity,         comprising administering an effective amount of a Compound of         the Invention, e.g., a compound according to any of Formula I or         1-1.122, or a composition comprising a Compound of the         Invention, e.g., a compound according to any of Formula I or         1-1.122, to a human or animal patient in need thereof. This         method also encompasses administering an effective amount of a         compound of formula I(i) or I(ii), in free or pharmaceutically         acceptable salt form. In another aspect, the invention provides         a method of treatment of the conditions disclosed above         comprising administering a therapeutically effective amount of a         Compound of Formula II, e.g., any of 2.1-2.64, or any of         Compound of Formula II(a)-II(e), in free or pharmaceutically         acceptable salt form, or a composition comprising the same, to a         human or animal patient in need thereof.

In an especially preferred embodiment, the invention provides methods of treatment or prophylaxis for narcolepsy. In this embodiment, PDE 1 Inhibitors may be used as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents. Thus, the invention further comprises a method of treating narcolepsy comprising administering simultaneously, sequentially, or contemporaneously administering therapeutically effective amounts of

-   -   (i) a PDE 1 Inhibitor of the Invention, e.g., a compound         according to any of Formula I or 1.1-1.122, or I(i) or I(ii);         and     -   (ii) a compound to promote wakefulness or regulate sleep, e.g.,         selected from (a) central nervous system stimulants-amphetamines         and amphetamine like compounds, e.g., methylphenidate,         dextroamphetamine, methamphetamine, and pemoline; (b)         modafinil, (c) antidepressants, e.g., tricyclics (including         imipramine, desipramine, clomipramine, and protriptyline) and         selective serotonin reuptake inhibitors (including fluoxetine         and sertraline); and/or (d) gamma hydroxybutyrate (GHB),         in free or pharmaceutically acceptable salt form, to a human or         animal patient in need thereof. In another embodiment, the         invention provides methods of treatment or prophylaxis for         narcolepsy as herein before described, wherein the PDE1         inhibitor is in a form of a pharmaceutical composition. In still         another embodiment, the methods of treatment or prophylaxis for         narcolepsy as hereinbefore described, comprises administering a         therapeutically effective amount of a Compound of Formula II,         e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or         pharmaceutically acceptable salt form, as a sole therapeutic         agent or use in combination for co-administered with another         active agent.

In another embodiment, the invention further provides methods of treatment or prophylaxis of a condition which may be alleviated by the enhancement of the progesterone signaling comprising administering an effective amount of a Compound of the Invention, e.g., a compound according to any of Formula 1-1.122 or Formula I, I(i) or I(ii) in free, pharmaceutically acceptable salt or prodrug form, to a human or animal patient in need thereof. The invention also provides methods of treatment as disclosed here, comprising administering a therapeutically effective amount of a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form. Disease or condition that may be ameliorated by enhancement of progesterone signaling include, but are not limited to, female sexual dysfunction, secondary amenorrhea (e.g., exercise amenorrhoea, anovulation, menopause, menopausal symptoms, hypothyroidism), pre-menstrual syndrome, premature labor, infertility, for example infertility due to repeated miscarriage, irregular menstrual cycles, abnormal uterine bleeding, osteoporosis, autoimmmune disease, multiple sclerosis, prostate enlargement, prostate cancer, and hypothyroidism. For example, by enhancing progesterone signaling, the PDE 1 inhibitors may be used to encourage egg implantation through effects on the lining of uterus, and to help maintain pregnancy in women who are prone to miscarriage due to immune response to pregnancy or low progesterone function. The novel PDE 1 inhibitors, e.g., as described herein, may also be useful to enhance the effectiveness of hormone replacement therapy, e.g., administered in combination with estrogen/estradiol/estriol and/or progesterone/progestins in postmenopausal women, and estrogen-induced endometrial hyperplasia and carcinoma. The methods of the invention are also useful for animal breeding, for example to induce sexual receptivity and/or estrus in a nonhuman female mammal to be bred.

In this embodiment, PDE 1 Inhibitors may be used in the foregoing methods of treatment or prophylaxis as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents, for example in conjunction with hormone replacement therapy. Thus, the invention further comprises a method of treating disorders that may be ameliorated by enhancement of progesterone signaling comprising administering simultaneously, sequentially, or contemporaneously administering therapeutically effective amounts of

-   -   (i) a PDE 1 Inhibitor, e.g., a compound according to any of         Formula 1.1-1.122 or Formula I, and     -   (ii) a hormone, e.g., selected from estrogen and estrogen         analogues (e.g., estradiol, estriol, estradiol esters) and         progesterone and progesterone analogues (e.g., progestins)         in free or pharmaceutically acceptable salt form, to a human or         animal patient in need thereof. In another embodiment, the         invention provides the method described above wherein the PDE 1         inhibitor is a Compound of Formula II, e.g., any of 2.1-2.64, or         any of Formula II(a)-II(e), in free or pharmaceutically         acceptable salt form.

The invention also provides a method for enhancing or potentiating dopamine D1 intracellular signaling activity in a cell or tissue comprising contacting said cell or tissue with an amount of a Compound of the Invention sufficient to inhibit PDE1B activity.

The invention also provides a method for enhancing or potentiating progesterone signaling activity in a cell or tissue comprising contacting said cell or tissue with an amount of a Compound of the Invention sufficient to inhibit PDE1B activity.

The invention also provides a method for treating a PDE1-related, especially PDE1B-related disorder, a dopamine D1 receptor intracellular signaling pathway disorder, or disorders that may be alleviated by the enhancement of the progesterone signaling pathway in a patient in need thereof comprising administering to the patient an effective amount of a Compound of the Invention that inhibits PDE1B, wherein PDE1B activity modulates phosphorylation of DARPP-32 and/or the GluR1AMPA receptor.

“The Compound of the Invention” referred to above includes a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form.

In another aspect, the invention also provides a method for the treatment for glaucoma or elevated intraocular pressure comprising topical administration of a therapeutically effective amount of a phosphodiesterase type I (PDE1) Inhibitor of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, in an opthalmically compatible carrier to the eye of a patient in need thereof. However, treatment may alternatively include a systemic therapy. Systemic therapy includes treatment that can directly reach the bloodstream, or oral methods of administration, for example.

The invention further provides a pharmaceutical composition for topical ophthalmic use comprising a PDE1 inhibitor; for example an ophthalmic solution, suspension, cream or ointment comprising a PDE1 Inhibitor of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or ophthamalogically acceptable salt form, in combination or association with an ophthamologically acceptable diluent or carrier.

Optionally, the PDE1 inhibitor may be administered sequentially or simultaneously with a second drug useful for treatment of glaucoma or elevated intraocular pressure. Where two active agents are administered, the therapeutically effective amount of each agent may be below the amount needed for activity as monotherapy. Accordingly, a subthreshold amount (i.e., an amount below the level necessary for efficacy as monotherapy) may be considered therapeutically effective and also may also be referred alternatively as an effective amount. Indeed, an advantage of administering different agents with different mechanisms of action and different side effect profiles may be to reduce the dosage and side effects of either or both agents, as well as to enhance or potentiate their activity as monotherapy.

The invention thus provides the method of treatment of a condition selected from glaucoma and elevated intraocular pressure comprising administering to a patient in need thereof an effective amount, e.g., a subthreshold amount, of an agent known to lower intraocular pressure concomitantly, simultaneously or sequentially with an effective amount, e.g., a subthreshold amount, of a PDE1 Inhibitor of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, such that amount of the agent known to lower intraocular pressure and the amount of the PDE1 inhibitor in combination are effective to treat the condition. In one embodiment, one or both of the agents are administered topically to the eye. Thus the invention provides a method of reducing the side effects of treatment of glaucoma or elevated intraocular pressure by administering a reduced dose of an agent known to lower intraocular pressure concomitantly, simultaneously or sequentially with an effective amount of a PDE1 inhibitor. However, methods other than topical administration, such as systemic therapeutic administration, may also be utilized.

The optional additional agent or agents for use in combination with a PDE1 inhibitor may, for example, be selected from the existing drugs comprise typically of instillation of a prostaglandin, pilocarpine, epinephrine, or topical beta-blocker treatment, e.g. with timolol, as well as systemically administered inhibitors of carbonic anhydrase, e.g. acetazolamide. Cholinesterase inhibitors such as physostigmine and echothiopate may also be employed and have an effect similar to that of pilocarpine. Drugs currently used to treat glaucoma thus include, e.g.,

-   -   1. Prostaglandin analogs such as latanoprost (Xalatan),         bimatoprost (Lumigan) and travoprost (Travatan), which increase         uveoscleral outflow of aqueous humor. Bimatoprost also increases         trabecular outflow.     -   2. Topical beta-adrenergic receptor antagonists such as timolol,         levobunolol (Betagan), and betaxolol, which decrease aqueous         humor production by the ciliary body.     -   3. Alpha₂-adrenergic agonists such as brimonidine (Alphagan),         which work by a dual mechanism, decreasing aqueous production         and increasing uveo-scleral outflow.     -   4. Less-selective sympathomimetics like epinephrine and         dipivefrin (Propine) increase outflow of aqueous humor through         trabecular meshwork and possibly through uveoscleral outflow         pathway, probably by a beta2-agonist action.     -   5. Miotic agents (parasympathomimetics) like pilocarpine work by         contraction of the ciliary muscle, tightening the trabecular         meshwork and allowing increased outflow of the aqueous humour.     -   6. Carbonic anhydrase inhibitors like dorzolamide (Trusopt),         brinzolamide (Azopt), acetazolamide (Diamox) lower secretion of         aqueous humor by inhibiting carbonic anhydrase in the ciliary         body.     -   7. Physostigmine is also used to treat glaucoma and delayed         gastric emptying.

For example, the invention provides pharmaceutical compositions comprising a PDE1 Inhibitor of the Invention and an agent selected from (i) the prostanoids, unoprostone, latanoprost, travoprost, or bimatoprost; (ii) an alpha adrenergic agonist such as brimonidine, apraclonidine, or dipivefrin and (iii) a muscarinic agonist, such as pilocarpine. For example, the invention provides ophthalmic formulations comprising a PDE-1 Inhibitor of the Invention together with bimatoprost, abrimonidine, brimonidine, timolol, or combinations thereof, in free or ophthamalogically acceptable salt form, in combination or association with an ophthamologically acceptable diluent or carrier. In addition to selecting a combination, however, a person of ordinary skill in the art can select an appropriate selective receptor subtype agonist or antagonist. For example, for alpha adrenergic agonist, one can select an agonist selective for an alpha 1 adrenergic receptor, or an agonist selective for an alpha₂ adrenergic receptor such as brimonidine, for example. For a beta-adrenergic receptor antagonist, one can select an antagonist selective for either β₁, or β₂, or β₃, depending on the appropriate therapeutic application. One can also select a muscarinic agonist selective for a particular receptor subtype such as M₁-M₅.

The PDE 1 inhibitor may be administered in the form of an ophthalmic composition, which includes an ophthalmic solution, cream or ointment. The ophthalmic composition may additionally include an intraocular-pressure lowering agent.

In yet another example, the PDE-1 Inhibitors disclosed may be combined with a subthreshold amount of an intraocular pressure-lowering agent which may be a bimatoprost ophthalmic solution, a brimonidine tartrate ophthalmic solution, or brimonidine tartratetimolol maleate ophthalmic solution.

In addition to the above-mentioned methods, it has also been surprisingly discovered that PDE1 inhibitors are useful to treat psychosis, for example, any conditions characterized by psychotic symptoms such as hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, and mania, such as in acute manic episodes and bipolar disorder. Without intending to be bound by any theory, it is believed that typical and atypical antipsychotic drugs such as clozapine primarily have their antagonistic activity at the dopamine D2 receptor. PDE1 inhibitors, however, primarily act to enhance signaling at the dopamine D1 receptor. By enhancing D1 receptor signaling, PDE1 inhibitors can increase NMDA receptor function in various brain regions, for example in nucleus accumbens neurons and in the prefrontal cortex. This enhancement of function may be seen for example in NMDA receptors containing the NR2B subunit, and may occur e.g., via activation of the Src and protein kinase A family of kinases.

Therefore, the invention provides a new method for the treatment of psychosis, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, and mania, such as in acute manic episodes and bipolar disorder, comprising administering an effective amount of a phosphodiesterase-1 (PDE1) Inhibitor of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, to a patient in need thereof.

PDE 1 Inhibitors may be used in the foregoing methods of treatment prophylaxis as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents. Thus, the invention further comprises a method of treating psychosis, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, or mania, comprising administering simultaneously, sequentially, or contemporaneously administering therapeutically effective amounts of:

-   -   (i) a PDE 1 Inhibitor of the invention, e.g., a Compound of         Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound         of Formula II, e.g., any of 2.1-2.64, or any of Formula         II(a)-II(e), in free or pharmaceutically acceptable salt form;         and     -   (ii) an antipsychotic, e.g.,

Typical antipsychotics, e.g.,

-   -   Butyrophenones, e.g. Haloperidol (Haldol, Serenace), Droperidol         (Droleptan);     -   Phenothiazines, e.g., Chlorpromazine (Thorazine, Largactil),         Fluphenazine (Prolixin), Perphenazine (Trilafon),         Prochlorperazine (Compazine), Thioridazine (Mellaril, Melleril),         Trifluoperazine (Stelazine), Mesoridazine, Periciazine,         Promazine, Triflupromazine (Vesprin), Levomepromazine (Nozinan),         Promethazine (Phenergan), Pimozide (Orap);     -   Thioxanthenes, e.g., Chlorprothixene, Flupenthixol (Depixol,         Fluanxol), Thiothixene (Navane), Zuclopenthixol (Clopixol,         Acuphase);

Atypical antipsychotics, e.g.,

-   -   Clozapine (Clozaril), Olanzapine (Zyprexa), Risperidone         (Risperdal), Quetiapine (Seroquel), Ziprasidone (Geodon),         Amisulpride (Solian), Paliperidone (Invega), Aripiprazole         (Abilify), Bifeprunox; norclozapine,

in free or pharmaceutically acceptable salt form, to a patient in need thereof.

In a particular embodiment, the Compounds of the Invention are particularly useful for the treatment or prophylaxis of schizophrenia.

Compounds of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, are particularly useful for the treatment of Parkinson's disease, schizophrenia, narcolepsy, glaucoma and female sexual dysfunction.

In still another aspect, the invention provides a method of lengthening or enhancing growth of the eyelashes by administering an effective amount of a prostaglandin analogue, e.g., bimatoprost, concomitantly, simultaneously or sequentially with an effective amount of a PDE1 inhibitor of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, to the eye of a patient in need thereof.

In yet another aspect, the invention provides a method for the treatment of traumatic brain injury comprising administering a therapeutically effective amount of a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, to a patient in need thereof. Traumatic brain injury (TBI) encompasses primary injury as well as secondary injury, including both focal and diffuse brain injuries. Secondary injuries are multiple, parallel, interacting and interdependent cascades of biological reactions arising from discrete subcellular processes (e.g., toxicity due to reactive oxygen species, overstimulation of glutamate receptors, excessive influx of calcium and inflammatory upregulation) which are caused or exacerbated by the inflammatory response and progress after the initial (primary) injury. Abnormal calcium homeostasis is believed to be a critical component of the progression of secondary injury in both grey and white matter. For a review of TBI, see Park et al., CMAJ (2008) 178(9):1163-1170, the contents of which are incorporated herein in their entirety. Studies have shown that the cAMP PKA signaling cascade is downregulated after TBI and treatment of PDE IV inhibitors such as rolipram to raise or restore cAMP level improves histopathological outcome and decreases inflammation after TBI. As Compounds of the present invention is a PDE1 inhibitor, it is believed that these compounds are also useful for the treatment of TBI, e.g., by restoring cAMP level and/or calcium homeostasis after traumatic brain injury.

The present invention also provides

-   -   (i) a Compound of the Invention for use as a pharmaceutical, for         example for use in any method or in the treatment of any disease         or condition as hereinbefore set forth,     -   (ii) the use of a Compound of the Invention in the manufacture         of a medicament for treating any disease or condition as         hereinbefore set forth,     -   (iii) a pharmaceutical composition comprising a Compound of the         Invention in combination or association with a pharmaceutically         acceptable diluent or carrier, and     -   (iv) a pharmaceutical composition comprising a Compound of the         Invention in combination or association with a pharmaceutically         acceptable diluent or carrier for use in the treatment of any         disease or condition as hereinbefore set forth.

Therefore, the invention provides use of a Compound of the Invention, e.g., a Compound of Formula I, e.g., any of 1.1-1.122, I(i) or I(ii), or a Compound of Formula II, e.g., any of 2.1-2.64, or any of Formula II(a)-II(e), in free or pharmaceutically acceptable salt form, for the manufacture of a medicament for the treatment or prophylactic treatment of the following diseases: Parkinson's disease, restless leg, tremors, dyskinesias, Huntington's disease, Alzheimer's disease, and drug-induced movement disorders; depression, attention deficit disorder, attention deficit hyperactivity disorder, bipolar illness, anxiety, sleep disorder, narcolepsy, cognitive impairment, dementia, Tourette's syndrome, autism, fragile X syndrome, psychostimulant withdrawal, and/or drug addiction; cerebrovascular disease, stroke, congestive heart disease, hypertension, pulmonary hypertension, and/or sexual dysfunction; asthma, chronic obstructive pulmonary disease, and/or allergic rhinitis, as well as autoimmune and inflammatory diseases; and/or female sexual dysfunction, exercise amenorrhoea, anovulation, menopause, menopausal symptoms, hypothyroidism, pre-menstrual syndrome, premature labor, infertility, irregular menstrual cycles, abnormal uterine bleeding, osteoporosis, multiple sclerosis, prostate enlargement, prostate cancer, hypothyroidism, estrogen-induced endometrial hyperplasia or carcinoma; and/or any disease or condition characterized by low levels of cAMP and/or cGMP (or inhibition of cAMP and/or cGMP signaling pathways) in cells expressing PDE1, and/or by reduced dopamine D1 receptor signaling activity; and/or any disease or condition that may be ameliorated by the enhancement of progesterone signaling; comprising administering an effective amount of a Compound of the Invention, or a pharmaceutical composition comprising a Compound of the Invention, to a patient in need of such treatment.

The invention also provides use of a Compound of the Invention for the manufacture of a medicament for the treatment or prophylactic treatment of:

-   -   a) glaucoma or elevated intraocular pressure,     -   b) psychosis, for example, any conditions characterized by         psychotic symptoms such as hallucinations, paranoid or bizarre         delusions, or disorganized speech and thinking, e.g.,         schizophrenia, schizoaffective disorder, schizophreniform         disorder, psychotic disorder, delusional disorder, and mania,         such as in acute manic episodes and bipolar disorder, or     -   c) traumatic brain injury.

The invention further provides use of the Compound of the Invention for lengthening or enhancing growth of the eyelashes.

The words “treatment” and “treating” are to be understood accordingly as embracing prophylaxis and treatment or amelioration of symptoms of disease as well as treatment of the cause of the disease.

Compounds of the Invention are in particular useful for the treatment of Parkinson's disease, narcolepsy and female sexual dysfunction.

For methods of treatment, the word “effective amount” is intended to encompass a therapeutically effective amount to treat a specific disease or disorder.

The term “pulmonary hypertension” is intended to encompass pulmonary arterial hypertension.

The term “patient” include human or non-human (i.e., animal) patient. In particular embodiment, the invention encompasses both human and nonhuman. In another embodiment, the invention encompasses nonhuman. In other embodiment, the term encompasses human.

The term “comprising” as used in this disclosure is intended to be open-ended and does not exclude additional, unrecited elements or method steps.

Compounds of the Invention may be used as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents. For example, as Compounds of the Invention potentiate the activity of D1 agonists, such as dopamine, they may be simultaneously, sequentially, or contemporaneously administered with conventional dopaminergic medications, such as levodopa and levodopa adjuncts (carbidopa, COMT inhibitors, MAO-B inhibitors), dopamine agonists, and anticholinergics, e.g., in the treatment of a patient having Parkinson's disease. In addition, the novel PDE 1 inhibitors of the Invention, e.g., the Compounds of the Invention as described herein, may also be administered in combination with estrogen/estradiol/estriol and/or progesterone/progestins to enhance the effectiveness of hormone replacement therapy or treatment of estrogen-induced endometrial hyperplasia or carcinoma.

Dosages employed in practicing the present invention will of course vary depending, e.g. on the particular disease or condition to be treated, the particular Compound of the Invention used, the mode of administration, and the therapy desired. Compounds of the Invention may be administered by any suitable route, including orally, parenterally, transdermally, or by inhalation, but are preferably administered orally. In general, satisfactory results, e.g. for the treatment of diseases as hereinbefore set forth are indicated to be obtained on oral administration at dosages of the order from about 0.01 to 2.0 mg/kg. In larger mammals, for example humans, an indicated daily dosage for oral administration will accordingly be in the range of from about 0.75 to 150 mg, conveniently administered once, or in divided doses 2 to 4 times, daily or in sustained release form. Unit dosage forms for oral administration thus for example may comprise from about 0.2 to 75 or 150 mg, e.g. from about 0.2 or 2.0 to 50, 75 or 100 mg of a Compound of the Invention, together with a pharmaceutically acceptable diluent or carrier therefor.

Pharmaceutical compositions comprising Compounds of the Invention may be prepared using conventional diluents or excipients and techniques known in the galenic art. Thus oral dosage forms may include tablets, capsules, solutions, suspensions and the like.

EXAMPLES

The synthetic methods for various Compounds of the Present Invention are illustrated below. Other compounds of the Invention and their salts may be made using the methods as similarly described below and/or by methods similar to those generally described in the detailed description and by methods known in the chemical art.

Example 1 7-Isobutyl-5-methyl-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-4-thioxo-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one

7-Isobutyl-5-methyl-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione (116 mg, 0.241 mmol) and P₂S₁₀ (214 mg, 0.284 mmol) are placed in a Biotage microwave vial, and then 2.3 mL of pyridine is added. The reaction mixture is heated in a microwave at 150° C. for 2.5 h. Pyridine is removed under high vacuum. The crude product is purified by silica gel flash chromatography to give 43.4 mg of pure product as pale yellow solids. MS (ESI) m/z 497.3 [M+H]⁺

Example 2 7-Isobutyl-5-methyl-4-(methylimino)-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one

7-Isobutyl-5-methyl-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-4-thioxo-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one (15 mg, 0.030 mmol) and HgCl₂ (16.4 mg, 0.060 mmol) are suspended in THF, and then 2.0 M methylamine solution in THF (240 μL, 0.12 mmol) is added. The reaction mixture is heated in a Biotage microwave at 110° C. for 5 hours. After routine workup, the mixture is purified by a semi-preparative HPLC to give pure product as white solids. MS (ESI) m/z 494.3 [M+H]⁺.

Example 3 2-(4-(1H-1,2,4-triazol-1-yl)benzyl)-5-methyl-7-neopentyl-3-(phenylamino)-4-thioxo-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one

The synthetic procedure of this compound is analogous to EXAMPLE 1 wherein 2-(4-(1H-1,2,4-triazol-1-yl)benzyl)-5-methyl-7-neopentyl-3-(phenylamino)-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione is used instead of 7-Isobutyl-5-methyl-3-(phenylamino)-2-(4-(pyridin-2-yl)benzyl)-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione. MS (ESI) m/z 501.2 [M+H]⁺.

Example 4 2-(4-(1H-1,2,4-triazol-1-yl)benzyl)-4-imino-5-methyl-7-neopentyl-3-(phenylamino)-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one

2-(4-(1H-1,2,4-triazol-1-yl)benzyl)-5-methyl-7-neopentyl-3-(phenylamino)-4-thioxo-4,5-dihydro-2H-pyrazolo[3,4-d]pyrimidin-6(7H)-one (60 mg, 0.12 mmol) and HgCl₂ (65 mg, 0.24 mmol) are suspended in 2 mL of 7N NH₃ in methanol. The reaction mixture is heated in a Biotage microwave at 110° C. for 3 hours. After routine workup, the mixture is purified by a semi-preparative HPLC to give 52 mg of pure product as off-white solids (yield: 90%). MS (ESI) m/z 484.3 [M+H]⁺.

Example 5 Measurement of PDE1B Inhibition In Vitro Using IMAP Phosphodiesterase Assay Kit

Phosphodiesterase 1B (PDE1B) is a calcium/calmodulin dependent phosphodiesterase enzyme that converts cyclic guanosine monophosphate (cGMP) to 5′-guanosine monophosphate (5′-GMP). PDE1B can also convert a modified cGMP substrate, such as the fluorescent molecule cGMP-fluorescein, to the corresponding GMP-fluorescein. The generation of GMP-fluorescein from cGMP-fluorescein can be quantitated, using, for example, the IMAP (Molecular Devices, Sunnyvale, Calif.) immobilized-metal affinity particle reagent.

Briefly, the IMAP reagent binds with high affinity to the free 5′-phosphate that is found in GMP-fluorescein and not in cGMP-fluorescein. The resulting GMP-fluorescein IMAP complex is large relative to cGMP-fluorescein. Small fluorophores that are bound up in a large, slowly tumbling, complex can be distinguished from unbound fluorophores, because the photons emitted as they fluoresce retain the same polarity as the photons used to excite the fluorescence.

In the phosphodiesterase assay, cGMP-fluorescein, which cannot be bound to IMAP, and therefore retains little fluorescence polarization, is converted to GMP-fluorescein, which, when bound to IMAP, yields a large increase in fluorescence polarization (Δmp) Inhibition of phosphodiesterase, therefore, is detected as a decrease in Δmp

Enzyme Assay

Materials: All chemicals are available from Sigma-Aldrich (St. Louis, Mo.) except for IMAP reagents (reaction buffer, binding buffer, FL-GMP and IMAP beads), which are available from Molecular Devices (Sunnyvale, Calif.).

Assay: 3′,5′-cyclic-nucleotide-specific bovine brain phosphodiesterase (Sigma, St. Louis, Mo.) is reconstituted with 50% glycerol to 2.5 U/ml. One unit of enzyme will hydrolyze 1.0 μmole of 3′,5′-cAMP to 5′-AMP per min at pH 7.5 at 30° C. One part enzyme is added to 1999 parts reaction buffer (30 μM CaCl₂, 10 U/ml of calmodulin (Sigma P2277), 10 mM Tris-HCl pH 7.2, 10 mM MgCl₂, 0.1% BSA, 0.05% NaN₃) to yield a final concentration of 1.25 mU/ml. 99 μl of diluted enzyme solution is added into each well in a flat bottom 96-well polystyrene plate to which 1 μl of test compound dissolved in 100% DMSO is added. Selected Compounds of the Invention are mixed and pre-incubated with the enzyme for 10 min at room temperature.

The FL-GMP conversion reaction is initiated by combining 4 parts enzyme and inhibitor mix with 1 part substrate solution (0.225 μM) in a 384-well microtiter plate. The reaction is incubated in dark at room temperature for 15 min. The reaction is halted by addition of 60 μl of binding reagent (1:400 dilution of IMAP beads in binding buffer supplemented with 1:1800 dilution of antifoam) to each well of the 384-well plate. The plate is incubated at room temperature for 1 hour to allow IMAP binding to proceed to completion, and then placed in an Envision multimode microplate reader (PerkinElmer, Shelton, Conn.) to measure the fluorescence polarization (Δmp)

A decrease in GMP concentration, measured as decreased Δmp, is indicative of inhibition of PDE activity. IC₅₀ values are determined by measuring enzyme activity in the presence of 8 to 16 concentrations of compound ranging from 0.0037 nM to 80,000 nM and then plotting drug concentration versus ΔmP, which allows IC₅₀ values to be estimated using nonlinear regression software (XLFit; IDBS, Cambridge, Mass.).

The Compounds of the Invention may be selected and tested in this assay to show PDE1 inhibitory activity. Exemplified compounds are shown to have IC₅₀ activities of less than 10 μM, e.g., Example 2 are shown to have an IC₅₀ of less than 200 nM.

Example 4 PDE1 Inhibitor Effect on Sexual Response in Female Rats

The effect of PDE1 inhibitors on Lordosis Response in female rats is measured as described in Mani, et al., Science (2000) 287: 1053. Ovariectomized and cannulated wild-type rats are primed with 2 μg estrogen followed 24 hours later by intracerebroventricular (icy) injection of progesterone (2 μg), PDE1 inhibitors of the present invention (0.1 mg, 1.0 mg or 2.5 mg) or sesame oil vehicle (control). The rats are tested for lordosis response in the presence of male rats. Lordosis response is quantified by the lordosis quotient (LQ=number of lordosis/10 mounts×100). The LQ for estrogen-primed female rats receiving Compounds of the Invention, at 0.1 mg, will likely be similar to estrogen-primed rats receiving progesterone and higher than for estrogen-primed rats receiving vehicle. 

1. A 3-amino-(optionally 4-imino or 4-thioxo)-4,5-dihydro-(1H or 2H)-pyrazolo[3,4-d]pyrimidin-6-ones in free or salt form.
 2. The compound according to claim 1, which is a compound of Formula II:

wherein (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—; (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl); (iii) R₂ is H, C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl or 2,2-dimethylpropyl) wherein said alkyl group is optionally substituted with one or more halo (e.g., fluoro) or hydroxy (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or 3-hydroxy-2-methylpropyl), haloC₁₋₆alkyl (e.g., trifluoromethyl or 2,2,2-trifluoroethyl), N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g., 2-(dimethylamino)ethyl or 2-aminopropyl), arylC₀₋₆alkyl (e.g., phenyl or benzyl), wherein said aryl is optionally substituted with one or more C₁₋₆alkoxy, for example, C₁₋₆alkoxyarylC₀₋₆alkyl (e.g., 4-methoxybenzyl), heteroarylC₀₋₆alkyl (e.g., pyridinylmethyl), wherein said heteroaryl is optionally substituted with one or more C₁₋₆alkoxy (e.g., C₁₋₆alkoxyheteroarylC₁₋₆alkyl); -G-J wherein G is a single bond or C₁₋₆alkylene (e.g., methylene) and J is C₃₋₈cycloalkyl or heteroC₃₋₈cycloalkyl (e.g., oxetan-2-yl, pyrrolidin-3-yl, pyrrolidin-2-yl) wherein the cycloalkyl and heterocycloalkyl group are optionally substituted with one or more C₁₋₆alkyl or amino, for example, —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., —C₀₋₄alkyl-cyclopentyl, —C₀₋₄alkyl-cyclohexyl or —C₀₋₄alkyl-cyclopropyl), wherein said cycloalkyl is optionally substituted with one or more C₁₋₆alkyl or amino (for example, 2-aminocyclopentyl or 2-aminocyclohexyl), —C₀₋₄alkyl-C₃₋₈heterocycloalkyl (e.g., —C₀₋₄alkyl-pyrrolidinyl, for example, —C₀₋₄alkylpyrrolidin-3-yl) wherein said heterocycloalkyl is optionally substituted with C₁₋₆alkyl (e.g., methyl), for example, 1-methylpyrrolidin-3-yl, 1-methyl-pyrrolindin-2-yl, 1-methyl-pyrrolindin-2-yl-methyl or 1-methyl-pyrrolindin-3-yl-methyl); (iv) R₃ is 1) -D-E-F wherein: D is a single bond, C₁₋₆alkylene (e.g., methylene), or arylC₁₋₆alkylene (e.g., benzylene or —CH₂C₆H₄—); E is a single bond, C₁₋₄alkylene (e.g., methylene, ethynylene, prop-2-yn-1-ylene), C₀₋₄alkylarylene (e.g., phenylene or —C₆H₄—, -benzylene- or —CH₂C₆H₄—), wherein the arylene group is optionally substituted with halo (e.g., Cl or F), heteroarylene (e.g., pyridinylene or pyrimidinylene), aminoC₁₋₆alkylene (e.g., —CH₂—N(H)—), amino (e.g., —N(H)—); C₃₋₈cycloalkylene optionally containing one or more heteroatom selected from N or O (e.g., piperidinylene), F is H, halo (e.g., F, Br, Cl), C₁₋₆alkyl (e.g., isopropyl or isobutyl), haloC₁₋₆alkyl (e.g., trifluoromethyl), aryl (e.g., phenyl), C₃₋₈cycloalkyl optionally containing one or more atom selected from a group consisting of N, S or O (e.g., cyclopentyl, cyclohexyl, piperidinyl, pyrrolidinyl, tetrahydro-2H-pyran-4-yl, or morpholinyl), and optionally substituted with one or more C₁₋₆alkyl (e.g., methyl or isopropyl), for example, 1-methylpyrrolidin-2-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, piperidin-2-yl, 1-methylpiperidin-2-yl, 1-ethylpiperidin-2-yl, heteroaryl (e.g., pyridyl (for example, pyrid-2-yl), pyrimidinyl (for example, pyrimidin-2-yl), thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl (e.g., pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for example, imidazol-1-yl, 4-methylimidazolyl, 1-methylimidazol-2-yl)), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl), alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), wherein said heteroaryl is optionally substituted with one or more C₁₋₆alkyl, halo (e.g., fluoro) or haloC₁₋₆alkyl; C₁₋₆alkoxy, —O-haloC₁₋₆alkyl (e.g., —O—CF₃), C₁₋₆alkylsulfonyl (for example, methylsulfonyl or —S(O)₂CH₃), —C(O)—R₁₃, wherein R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g., methyl), —OC₁₋₆alkyl (e.g., —OCH₃), haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g., phenyl), or heteroaryl; —N(R₁₄)(R₁₅); or 2) a substituted heteroarylC₁₋₆alkyl, e.g., substituted with haloC₁₋₆alkyl; or 3) attached to one of the nitrogens on the pyrazolo portion of Formula II and is a moiety of Formula A

wherein: X, Y and Z are, independently, N or C, R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F); and R₁₀ is  halogen (e.g., fluoro or chloro),  C₁₋₆alkyl,  C₃₋₈cycloalkyl,  heteroC₃₋₈cycloalkyl (e.g., pyrrolidinyl or piperidinyl),  haloC₁₋₆alkyl (e.g., trifluoromethyl),  aryl (e.g., phenyl) or heteroaryl (e.g., pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl), alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl),  C₁₋₆alkyl sulfonyl (e.g., methyl sulfonyl),  arylcarbonyl (e.g., benzoyl),  heteroarylcarbonyl,  C₁₋₆alkoxycarbonyl, (e.g., methoxycarbonyl),  Aminocarbonyl,  —N(R₁₄)(R₁₅);  wherein said aryl, heteroaryl, cycloalkyl or heterocycloalkyl is optionally substituted with one or more C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl)  preferably R₁₀ is phenyl, pyridyl, e.g., 2-pyridyl, pyrrolidinyl or piperidinyl is optionally substituted with one or more C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl); provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀, respectively, is not present; (v) R₄ and R₅ are independently: H, C₁₋₆alkyl (e.g., methyl, isopropyl, isobutyl, n-propyl), C₃₋₈cycloalkyl (e.g., cyclopentyl or cyclohexyl), C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl (for example pyrrolidin-3-yl or pyrrolidin-1-yl), piperidinyl (for example, piperidin-1-yl), morpholinyl), —C₀₋₆alkylaryl (e.g., phenyl or benzyl) or —C₀₋₆alkylheteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or pyrazol-3-yl) wherein said aryl or heteroaryl is optionally substituted with one or more halo (e.g., 4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group (e.g., biphenyl-4-ylmethyl); (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl or ethyl) or C₃₋₈cycloalkyl; (vii) R₁₄ and R₁₅ are independently H or C₁₋₆alkyl, in free or salt form.
 3. The compound according to claim 2, which compound is a Compound of Formula II, wherein: (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—; (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl); (iii) R₂ is C₁₋₆alkyl (e.g., isopropyl, isobutyl, 2-methylbutyl or 2,2-dimethylpropyl) wherein said alkyl group is optionally substituted with one or more halo (e.g., fluoro) or hydroxy (e.g., hydroxyC₁₋₆alkyl, for example 1-hydroxyprop-2-yl or 3-hydroxy-2-methylpropyl), (iv) R₃ is attached to one of the nitrogens on the pyrazolo portion of Formula II and is a moiety of Formula A

wherein: X, Y and Z are, independently, N or C, R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F); and R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl, optionally substituted with one or more C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl); provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀, respectively, is not present; (i) R₄ is H and R₅ phenyl optionally substituted with one or more halo (e.g., 4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group (e.g., biphenyl-4-ylmethyl); (ii) R₆ is H or C₁₋₆alkyl (e.g., methyl or ethyl); (iii) R₁₄ and R₁₅ are independently H or C₁₋₆alkyl, in free or salt form.
 4. The compound according to claim 1, which compound is a Compound of formula I

wherein (i) Q is —C(═S)—, —C(═N(R₆))— or —C(R₁₄)(R₁₅)—; (ii) R₁ is H or C₁₋₆alkyl (e.g., methyl or ethyl); (iii) R₂ is H, C₁₋₆alkyl (e.g., isopropyl, isobutyl, neopentyl, 2-methylbutyl, 2,2-dimethylpropyl) wherein said alkyl group is optionally substituted with halo (e.g., fluoro) or hydroxy (e.g., 1-hydroxypropan-2-yl, 3-hydroxy-2-methylpropyl), —C₀₋₄alkyl-C₃₋₈cycloalkyl (e.g., cyclopentyl, cyclohexyl) optionally substituted with one or more amino (e.g., —NH₂), for example, 2-aminocyclopentyl or 2-aminocyclohexyl), wherein said cycloalkyl optionally contains one or more heteroatom selected from N and O and is optionally substituted with C₁₋₆alkyl (e.g., 1-methyl-pyrrolindin-2-yl, 1-methyl-pyrrolindin-3-yl, 1-methyl-pyrrolindin-2-yl-methyl or 1-methyl-pyrrolindin-3-yl-methyl), C₃₋₈heterocycloalkyl (e.g., pyrrolidinyl, for example, pyrrolidin-3-yl) optionally substituted with C₁₋₆alkyl (e.g., methyl), for example, 1-methylpyrrolidin-3-yl, C₃₋₈cycloalkyl-C₁₋₆alkyl (e.g., cyclopropylmethyl), haloC₁₋₆alkyl (e.g., trifluoromethyl, 2,2,2-trifluoroethyl), —N(R₁₄)(R₁₅)—C₁₋₆alkyl (e.g., 2-(dimethylamino)ethyl,2-aminopropyl), hydroxyC₁₋₆alkyl (e.g., (e.g., 3-hydroxy-2-methylpropyl, 1-hydroxyprop-2-yl), arylC₁₋₆alkyl (e.g., benzyl), heteroarylC₁₋₆alkyl (e.g., pyridinylmethyl), C₁₋₆ alkoxyarylC₁₋₆alkyl (e.g., 4-methoxybenzyl); -G-J wherein: G is a single bond or, alkylene (e.g., methylene); J is cycloalkyl or heterocycloalkyl (e.g., oxetan-2-yl, pyrolyin-3-yl, pyrolyin-2-yl) optionally substituted with C₁₋₆alkyl (e.g., (1-methylpyrrolidin-2-yl)); (iv) R₃ is 1) -D-E-F wherein: D is a single bond, C₁₋₆alkylene (e.g., methylene), or arylalkylene (e.g., pbenzylene or —CH₂C₆H₄—); E is a single bond, C₁₋₄alkylene (e.g., methylene, ethynylene, prop-2-yn-1-ylene), —C₀₋₄alkylarylene (e.g., phenylene or —C₆H₄—, -benzylene- or CH₂C₆H₄—), wherein the arylene group is optionally substituted with halo (e.g., Cl or F), heteroarylene (e.g., pyridinylene or pyrimidinylene), aminoC₁₋₆alkylene (e.g., —CH₂—N(H)—), amino (e.g., —N(H)—); C₃₋₈cycloalkylene optionally containing one or more heteroatom selected from N or O (e.g., piperidinylene), F is H, halo (e.g., F, Br, Cl), C₁₋₆alkyl (e.g., isopropyl or isobutyl), haloC₁₋₆alkyl (e.g., trifluoromethyl), aryl (e.g., phenyl), C₃₋₈cycloalkyl optionally containing at least one atom selected from a group consisting of N or O (e.g., cyclopentyl, cyclohexyl, piperidinyl, pyrrolidinyl, tetrahydro-2H-pyran-4-yl, or morpholinyl), and optionally substituted with C₁₋₆alkyl (e.g., methyl or isopropyl), for example, 1-methylpyrrolidin-2-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, piperidin-2-yl, 1-methylpiperidin-2-yl, 1-ethylpiperidin-2-yl, heteroaryl optionally substituted with C₁₋₆alkyl, (e.g., pyridyl, (for example, pyrid-2-yl), pyrimidinyl (for example, pyrimidin-2-yl), thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl (e.g., pyrazolyl (for example, pyrazol-1-yl) or imidazolyl (for example, imidazol-1-yl, 4-methylimidazolyl, 1-methylimidazol-2-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl), alkoxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), wherein said heteroaryl is optionally substituted with halo (e.g., fluoro) or haloC₁₋₆alkyl; amino (e.g., —NH₂), C₁₋₆alkoxy, —O-haloC₁₋₆alkyl (e.g., —O—CF₃), C₁₋₆alkylsulfonyl (for example, methylsulfonyl or —S(O)₂CH₃), —C(O)—R₁₃, —N(R₁₄)(R₁₅); or 2) a substituted heteroarylaklyl, e.g., substituted with haloalkyl; or 3) attached to one of the nitrogens on the pyrazolo portion of Formula I and is a moiety of Formula A

wherein X, Y and Z are, independently, N or C, and R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F); and R₁₀ is halogen, alkyl, cycloalkyl, haloalkyl (e.g., trifluoromethyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl), alkoxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl), alkyl sulfonyl (e.g., methyl sulfonyl), arylcarbonyl (e.g., benzoyl), or heteroarylcarbonyl, alkoxycarbonyl, (e.g., methoxycarbonyl), aminocarbonyl; preferably phenyl or pyridyl, e.g., 2-pyridyl; provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀, respectively, is not present; (v) R₄ and R₅ are independently H, C₁₋₆alkyl (e.g., methyl, isopropyl), C₃₋₈cycloalkyl (e.g., cyclopentyl), C₃₋₈heterocycloalkyl (e.g., pyrrolidin-3-yl), aryl (e.g., phenyl) or heteroaryl (e.g., pyrid-4-yl, pyrid-2-yl or pyrazol-3-yl) wherein said aryl or heteroaryl is optionally substituted with halo (e.g., 4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkoxy, C₁₋₆alkyl, or another aryl group (e.g., biphenyl-4-ylmethyl); (vi) R₆ is H, C₁₋₆alkyl (e.g., methyl) or C₃₋₈cycloalkyl; (vii) R₁₃ is —N(R₁₄)(R₁₅), C₁₋₆alkyl (e.g., methyl), —OC₁₋₆alkyl (e.g., —OCH₃), haloC₁₋₆alkyl(trifluoromethyl), aryl (e.g., phenyl), or heteroaryl; and (viii) R₁₄ and R₁₅ are independently H or C₁₋₆alkyl, in free or salt form.
 5. The compound according to claim 2 wherein R₃ is attached to one of the nitrogens on the pyrazolo portion of Formula II and is a moiety of

wherein: X, Y and Z are, independently, N or C, R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F); and R₁₀ is phenyl or pyridyl, e.g., 2-pyridyl, or pyrrolidinyl optionally substituted with one or more C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl); provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀, respectively, is not present in free or salt form.
 6. The compound according to claim 2 wherein R₁ is C₁₋₆alkyl, in free or salt form.
 7. The compound according to claim 6 wherein R₂ is C₁₋₆alkyl, in free or salt form.
 8. The compound according to claim 7 wherein R₄ is H and R₅ is optionally substituted with halo, hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group, in free or salt form.
 9. The compound according to claim 1 selected from any of the following:

in free or salt form.
 10. The compound according to claim 1 wherein the compound is:

in free or salt form.
 11. The compound according to claim 1 wherein the compound is:

in free or salt form.
 12. The compound according to claim 1, wherein the compound is:

in free or salt form.
 13. The compound according to claim 1, wherein the compound is:

in free or salt form.
 14. A pharmaceutical composition comprising a compound according to claim 2, in free or pharmaceutically acceptable salt form, in admixture with a pharmaceutically acceptable diluent or carrier.
 15. A method for the treatment or prophylaxis of any of the following conditions: Parkinson's disease, restless leg, tremors, dyskinesias, Huntington's disease, Alzheimer's disease, and drug-induced movement disorders; depression, attention deficit disorder, attention deficit hyperactivity disorder, bipolar illness, anxiety, sleep disorder, narcolepsy, cognitive impairment, dementia, Tourette's syndrome, autism, fragile X syndrome, psychostimulant withdrawal, and/or drug addiction; cerebrovascular disease, stroke, congestive heart disease, hypertension, pulmonary hypertension, and/or sexual dysfunction; asthma, chronic obstructive pulmonary disease, and/or allergic rhinitis, as well as autoimmune and inflammatory diseases; and/or female sexual dysfunction, exercise amenorrhoea, anovulation, menopause, menopausal symptoms, hypothyroidism, pre-menstrual syndrome, premature labor, infertility, irregular menstrual cycles, abnormal uterine bleeding, osteoporosis, multiple sclerosis, prostate enlargement, prostate cancer, hypothyroidism, estrogen-induced endometrial hyperplasia or carcinoma; and/or any disease or condition characterized by low levels of cAMP and/or cGMP (or inhibition of cAMP and/or cGMP signaling pathways) in cells expressing PDE1, and/or by reduced dopamine D1 receptor signaling activity; and/or any disease or condition that may be ameliorated by the enhancement of progesterone signaling; comprising administering a therapeutically effective amount of a compound according to claim 2, in free or pharmaceutically acceptable salt form.
 16. The method of claim 15, wherein the condition is Parkinson's disease.
 17. The method of claim 15, wherein the condition is cognitive impairment.
 18. The method of claim 15, wherein the condition is narcolepsy.
 19. The method of claim 18 further comprising administering a compound or compounds selected from central nervous system stimulants, modafinil, antidepressants, and gamma hydroxybutyrate, to a patient in need thereof.
 20. The method of claim 15, wherein said condition is female sexual dysfunction.
 21. The method of claim 20, further comprising administering a compound or compounds selected from a group consisting of estradiol, estriol, estradiol esters, progesterone and progestins to a patient in need thereof.
 22. A method for the treatment for glaucoma or elevated intraocular pressure comprising topical administration of a therapeutically effective amount of a compound according to claim 2, in free or pharmaceutically acceptable salt form, to a patient in need of such treatment.
 23. A pharmaceutical composition comprising a compound according to claim 2, in free or opthamologically acceptable salt form, in combination or association with an opthamologically acceptable diluents or carrier.
 24. A method for the treatment or prophylaxis of psychosis including schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, and mania, such as in acute manic episodes and bipolar disorder, comprising administering an effective amount of a compound according to claim 2, in free or pharmaceutically acceptable salt form. 25-28. (canceled)
 29. The compound according to claim 2, wherein (i) Q is —C(═S)— or —C(═N(R₆))—; (ii) R₁ is C₁₋₆alkyl (e.g., methyl or ethyl); (iii) R₂ is 2,2-dimethylpropyl; (iv) R₃ is attached to one of the nitrogens on the pyrazolo portion of Formula II and is a moiety of Formula A

wherein: X, Y and Z are, independently, N or C, R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F); and R₁₀ is heteroaryl (e.g., pyridyl, (for example, pyrid-2-yl) or e.g., thiadiazolyl (for example, 1,2,3-thiadiazol-4-yl), diazolyl, triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl (e.g., tetrazol-5-yl), alkyloxadiazolyl (e.g., 5-methyl-1,2,4-oxadiazol), pyrazolyl (e.g., pyrazol-1-yl), wherein said heteroaryl is optionally substituted with one or more C₁₋₆alkyl (e.g., methyl), halogen (e.g., chloro or fluoro), haloC₁₋₆alkyl (e.g., trifluoromethyl), hydroxy, carboxy, —SH or an additional aryl or heteroaryl (e.g., biphenyl or pyridylphenyl) provided that when X, Y or X is nitrogen, R₈, R₉ or R₁₀, respectively, is not present; (v) R₄ is H and R₅ is phenyl optionally substituted with one or more halo (e.g., 4-fluorophenyl), hydroxy (e.g., 4-hydroxyphenyl), C₁₋₆alkyl, C₁₋₆alkoxy or another aryl group (e.g., biphenyl-4-ylmethyl); (vi) R₆ is H, in free or salt form.
 30. The compound according to claim 29, wherein: (i) Q is —C(═S)—; (ii) R₁ is methyl; (iii) X, Y and Z are C; (iv) R₈, R₉, R₁₁ and R₁₂ are H; and (v) R₁₀ is triazolyl (e.g., 1,2,4-triazol-1-yl), in free or salt form. 